Impact of ultrasonication on the physicochemical, pasting, amino acid, mineral, phenolic, and sugar profile of germinated brown rice from various varieties

Swasti Mudgal; Narpinder Singh

doi:10.1007/s13197-024-06039-4

. 2024 Aug 13;62(3):492–507. doi: 10.1007/s13197-024-06039-4

Impact of ultrasonication on the physicochemical, pasting, amino acid, mineral, phenolic, and sugar profile of germinated brown rice from various varieties

Swasti Mudgal ¹, Narpinder Singh ^1,^2,^✉

PMCID: PMC11794897 PMID: 39917347

Abstract

Germinated rice, recognized for its enhanced nutritional and functional properties, is a subject of increasing interest due to its potential health benefits. Ultrasonic low-frequency sound waves (40 kHz) treatment of seeds is a green technology that promises to enhance germination capacity of the grains and functional and biochemical properties through the stimulation of water-oxygen uptake and seed metabolism. Ultrasonication treatment (5, 10 and 15 min) significantly enhanced the protein and total dietary fibre content of (brown rice) BR from different varieties. Results showed that ultrasonication accelerated starch and phytic acid degradation and increased the reduced sugar content via activation of alpha-amylase. Moreover, the ultrasonically treated BR had higher levels of gamma-aminobutyric acid, essential amino acids and other bioactive compounds. Ultrasonicated germinated grain can be utilize further by food industry for making functional foods.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-06039-4.

Keywords: Ultrasonication, Germinated rice, Amino acid profile, Pasting properties, Phenolic profile

Introduction

Germination is a natural biochemical process that can significantly increase the beneficial nutrients of whole grains. Germinated grains have been utilized as materials in the food industry to boost the nutritional content, mineral uptake, taste, and flavor of the finished products (Guzmán-Ortiz et al. 2019). The germination process involves three stages: soaking or hydration, incubation for sprouting, and drying. The whole (brown rice) BR usually requires 72 h to germinate. Germination improves nutritional qualities and decreases non-nutrient components such as phytic acid. Compared with BR, germinated BR is a more nutritious diet with a pleasant flavor and a high content of bioactive components and is simple to digest (Jabeen et al. 2023). Jiamyangyuen and Ooraikul (2008) stated that when rice was soaked and germinated for a longer period of time, the effect of germination on the physiochemical and nutritional qualities of rice flour were more prominent. The complexity of grain germination requires soaking for 24–48 h before the initiation of subsequent metabolism, making this a highly time-consuming procedure. Therefore, soaking whole brown grains in water is a significant step toward achieving the desired moisture content (> 30% db) (Miano and Augusto 2018). Hydration is predominantly a mass transfer process that involves either diffusion or capillary flow, depending on the morphology and content of the grains. Several priming approaches for decreasing soaking time and improving seedling growth have recently been investigated. Ultrasonication, as a non-thermal, non-toxic, highly efficient, and nature friendly technology of physical stimulation, has been used to increase the germination rate, promote sprout growth, and promote health (Ding et al. 2018a). The ultrasonic process in the liquid medium produces cavitation bubbles as a result of the waves diffusing and exciting the molecules through a sequence of rarefaction and contraction cycles, which modify the physio-chemical and biochemical properties of BR, leading to enhanced bioactive, functional and nutritional components along with a reduction in processing time and anti-nutritional components (Ding et al. 2018b). Ultrasound is a well-established technique with potential applications in the food industries related to development of new products using germinated grains. This study aimed to determine the best ultrasonication time for enhancing the germination of basmati and non-basmati varieties, on the basis of their physicochemical, amino acid, mineral, sugar, phenolic, and pasting properties and a comprehensive comparison was performed among BR, control germinated BR and ultrasonicated-germinated BR.

Materials and methods

Material and sample preparation

BR from different basmati (PB1121, PB1509, CSR30 and PB1637) and non-basmati (PR113, PR121, PR124 and PR129) were collected for the germination process and acquired from the Punjab Rice Research Centre in December 2020. The 2.5% NaClO solution for 5 min was used to disinfect the grains before soaking and subsequently washed thoroughly with water. The germination process was carried out by soaking each variety grain in water (1:2 ratio) ultrasonication treatment was given for 5, 10, and 15 min during soaking stage using an ultrasonic generator (Cole-Parmer 750-W, ultrasonic homogenizer) equipped with a probe transducer (Cole-Parmer) at 40 kHz at room temperature and 30% amplitude, then soaked grains were incubated for 24 h at 32 °C in an incubator for germination. Germinated grains were oven-dried at 35 ± 2 °C for 12 h, and dried germinated grain was ground by using a super-mill and sieved through a 60-mesh sieve and stored at −18 °C for further analysis. Control germinated and ultrasonicated germinated BR treated for 5, 10 and 15 min were designated as the Germ Cont (Controlled germination), US 5 min, US 10 min, and US 15 min, respectively.

Proximate analysis

The ash content (AsC), and protein content (PC) of the prepared samples were analysed by the AACC-sanctioned procedure (AACC International 2000). A nitrogen content of 5.95 was used for the calculation of PC. A specific enzyme assay kit (Megazyme International, Ireland) was used to analyze the total dietary fiber (TDF) and total starch (TS) contents. The lipid content (LC) was determined using the AOAC (1990) method. The alpha-amylase activity was estimated by a colorimetric technique using Megazyme (Megazyme International, ICC Standard No. 303, Ireland) and measured in units per gram of dry matter (U/g dw).

Phenolics extraction and analysis

The free, and bound phenolics were isolated from BR by following the procedure given in Mudgal and Singh (2022). The identification of free and bound phenolics was performed using high-performance liquid chromatography (HPLC) (Agilent 1260 Infinity, a DAD-PDA with binary pump), a C-18 column, and an automatic sample injector. Specific analytical standards, such as gallic, p-coumaric, vanillic, ferulic acid, and 4-hydroxybenzoic acid, were employed for the quantification of different phenolic components. The mobile phase comprises (0.1%) 2,2,2-trifluoracetic acid in water (I) and (50%) ACN (II), water (49.8%), and (0.2%) 2,2,2-trifluoracetic acid at a rate of 1 mL min − 1. Using a C18 column in a column oven kept at 30 °C, the peaks of phenolic components were found at various wavelengths (367, 350, 320, and 280 nm). The EZChrom Elite software (version 3.2.0, Santa Clara, CA, USA) from Agilent Solutions was used to identify and calculate the area under the peaks. The results are presented as mg/kg on a dw basis.

Pasting properties

A Rapid Visco Analyzer (RVA) (Newport Scientific, 3D + , Warrie-wood, Australia) was used to evaluate the pasting properties, such as the pasting temperature (PT), peak viscosity (PV), breakdown viscosity (BDV), final viscosity (FV), and set-back viscosity (SBV), of the samples as described in Mudgal and Singh (2024).

Mineral and phytic acid composition

The mineral composition, including the calcium, zinc, phosphorous, potassium, magnesium, and iron contents, of the samples was evaluated using an atomic absorption spectrophotometer (AAS) (Agilent Technology) (Bhinder et al. 2021) with the AACC 2000 Method (08-01).

Sugar profile by HPLC-PAD

The sugar profile of the samples was prepared and analysed as mentioned in Banura and Singh (2023). A Metrosep Carb 2-250/4.0 column, which contained in a CT 2.1 column oven thermostat kept at 30 °C, was used to separate the compounds. The mobile phase contained 10 mmol L⁻¹ sodium acetate and 100 mmol L⁻¹ sodium hydroxide at a pressure of 15 MPa and a flow rate of 0.5 mL min⁻¹. A Professional Detector Vario (PAD 945) (Metrohm AG, Herisau, Switzerland) was used for the system. Metrohm AG software, termed MagIC Net (version 3.2), was used to process the chromatograms.

Amino acid composition

A Shimadzu LC-30 AD HPLC system was employed to determine the amino acids (AAs) and the samples were made in the same manner, as previously described Pal et al. (2016). GABA, leucine, isoleucine, histidine, lysine, threonine, phenylalanine, methionine, arginine, glycine, tyrosine, valine, proline, glutamic acid, alanine, serine and aspartic acid were analyzed in a working standard AAs mixture (Thermo Scientific Amino Acid Standard H, Prod NCI0180). LAB Solutions software (5.54SP 5) was used to evaluate the obtained peaks. The AAs in all samples were determined through analyzing retention times and characterized by contrasting the sample’s area ratio to that of the reference standard AAs. The AAs contents are presented in milligrams per gram of sample.

Statistical analysis

The experimental readings were taken as an average of three readings for each sample. All the data are presented as the mean and standard deviation. One-way analysis of variance (ANOVA) and paired t-test were used for statistical analysis, and the software MINITAB® version 14.12.0 was used for data analysis.

Results and discussion

Proximate composition

Table 1 presents the proximate composition including the PC, AsC, LC, and TDF contents, of BR, control-germinated, and ultrasonicated-germinated BR from different varieties. Statistical analysis ANOVA indicated that ultrasonication and variety significantly influenced the proximate composition (Table S1, p < 0.05). The F values indicated that the impact of variety on PC, AsC, TDF, and LC was more pronounced compared that of ultrasonication. Germination caused an increase in PC, AsC, and TDF, while LC decreased in all the control-germinated BR. The increased values of PC, AsC, and TDF for the control-germinated BR ranged from 9.37 to 10.38%, 0.62 to 1.34%, and 3.1 to 6.0%, respectively, while those of BR ranged from 8.7 to 9.9%, 0.56 to 1%, and 2.7 to 5.7%, respectively. The ultrasonic-germinated had a significant impact on the proximate composition, including the contents of PC, AsC, LC, and TDF, of all the varieties (Table S1). The results indicated that ultrasonication had a maximum impact on PC and TDF, leading to increases of up to 12.8% and 26%, respectively, for PB1509 US for 15 min. However, AsC and LC decreased with increasing ultrasonication time, and the maximum decrease in AsC (49%) was observed for PR121 US for 15 min. The ultrasonication process created fissures on the grain’s outermost surface, promoting the discharge of inorganic minerals into the soaking water, could be reason of reduction in the AsC content in all ultrasonicated-germinated BR (López-Ribera and Vicient 2017; Bhinder et al. 2021). The LC of the BR-treated and control germinated basmati and non-basmati BR ranged from 2.4 to 3.9% and from 2.2 to 3.7%, respectively. Ultrasound pretreatment further lowered the LC, and a maximum decrease of 39% was observed for PB1637 US for 15 min. The decrease in LC may be attributed to the consumption of fat deposits that assisted the catabolic activities of seeds during sprouting, which led to a reduction in LC (Prabhakar et al. 2021). The increase in PC during germination can be attributed to the consumption of carbohydrates/starch and lipids that provide energy for seed expansion during germination as well as the release of free AAs through enzymatic hydrolysis, which led to the synthesis of more proteins (Prabhakar et al. 2021). Moreover, another reason could be that the reduction in dry matter owing to respiration and germination might have contributed to the increase in PC and TDF after germination.

Table 1.

Proximate composition of BR, germinated control BR, ultrasonicated (5, 10 and 15 min) germinated BR from various non-basmati and basmati varieties

Variety	Treatment	AsC (%)	PC (%)	TDF (%)	LC (%)	TS (%)	Amylase activity (U/g)
Non-basmati
PR113	BR	0.50 ± 0.040^g	9.48 ± 0.13^hi	2.7 ± 0.94ⁱ	3.73 ± 0.044^b	70.7 ± 0.023^ab	0.19 ± 0.018^hi
	Germ. cont.	0.62 ± 0.008^e	9.57 ± 0.08^gh	3 ± 0.04^h	3.56 ± 0.043^c	67.8 ± 0.036^c	19.4 ± 0.54^f
	US 5 min	0.41 ± 0.002ⁱ	9.84 ± 0.012^de	3.1 ± 0.031^gh	3.42 ± 0.041^de	66.5 ± 0.019^fg	23.0 ± 0.65^bc
	US 10 min	0.38 ± 0.001^ij	9.88 ± 0.017^cd	3.5 ± 0.035^g	2.96 ± 0.039^hi	65.7 ± 0.017^gh	26.4 ± 0.68^a
	US 15 min	0.31 ± 0.003^jk	9.62 ± 0.013^f	2.9 ± 0.030^hi	3.55 ± 0.039^cd	67.0 ± 0.023^de	20.6 ± 0.64^de
PR121	BR	0.61 ± 0.002^ef	9.30 ± 0.011^ij	3.6 ± 0.60^f	3.91 ± 0.047^a	70.0 ± 0.038^b	0.18 ± 0.021ⁱ
	Germ. cont.	0.69 ± 0.005^de	9.61 ± 0.07^fg	3.9 ± 0.05^e	3.74 ± 0.046^ab	66.8 ± 0.034^ef	19.0 ± 0.52^jh
	US 5 min	0.48 ± 0.002^gh	9.85 ± 0.015^d	4.0 ± 0.040^de	3.65 ± 0.047^bc	66.2 ± 0.033^g	20.5 ± 0.53^e
	US 10 min	0.43 ± 0.001^hi	10.42 ± 0.017^a	4.4 ± 0.044^cd	3.14 ± 0.040^fg	65.6 ± 0.028^h	23.5 ± 0.54^ab
	US 15 min	0.31 ± 0.003^j	9.94 ± 0.015^c	4.3 ± 0.043^d	3.41 ± 0.041^e	66.6 ± 0.031^f	23.1 ± 0.49^b
PR124	BR	0.93 ± 0.005^ab	9.10 ± 0.12^j	5.7 ± 0.42^c	3.43 ± 0.041^d	68.1 ± 0.037^bc	0.14 ± 0.032^j
	Germ. cont.	0.99 ± 0.009^a	9.37 ± 0.07ⁱ	6.0 ± 0.07^bc	3.20 ± 0.042^f	64.5 ± 0.033^hi	18.7 ± 0.48^h
	US 5 min	0.81 ± 0.005^b	9.54 ± 0.013^h	6.1 ± 0.060^b	3.13 ± 0.038^g	64.2 ± 0.028^ij	19.2 ± 0.45^j
	US 10 min	0.75 ± 0.004^c	9.67 ± 0.015^e	6.5 ± 0.065^a	2.75 ± 0.033^j	63.5 ± 0.019^j	22.3 ± 0.57^c
	US 15 min	0.70 ± 0.006^d	9.63 ± 0.017^ef	6.3 ± 0.063^ab	2.90 ± 0.035^ij	64.3 ± 0.024ⁱ	20.8 ± 0.54^d
PR129	BR	0.72 ± 0.07^cd	9.60 ± 0.10^g	3.4 ± 0.54^fg	3.37 ± 0.040^ef	71.3 ± 0.039^a	0.17 ± 0.065^ij
	Germ. cont.	0.78 ± 0.008^bc	9.93 ± 0.08^c	3.6 ± 0.05^f	3.11 ± 0.042^gh	67.7 ± 0.037^c	19.3 ± 0.58^fj
	US 5 min	0.59 ± 0.003^f	10.31 ± 0.019^b	3.7 ± 0.037^ef	2.94 ± 0.035ⁱ	67.2 ± 0.029^d	19.8 ± 0.49^ef
	US 10 min	0.51 ± 0.002^fg	10.38 ± 0.018^ab	4.0 ± 0.040^de	2.72 ± 0.033^jk	66.8 ± 0.024^e	23.0 ± 0.53^bc
	US 15 min	0.44 ± 0.004^h	10.21 ± 0.020^bc	3.9 ± 0.039^e	3.03 ± 0.036^h	67.6 ± 0.022^cd	21.2 ± 0.51^cd
Basmati
PB1121	BR	0.98 ± 0.06^de	9.90 ± 0.07^g	5.5 ± 0.8^ef	3.18 ± 0.038^b	68.8 ± 0.037^c	0.21 ± 0.026^h
	Germ. cont.	1.14 ± 0.008^b	10.35 ± 0.019^de	5.7 ± 0.057^de	2.93 ± 0.035^c	65.3 ± 0.032^h	24.6 ± 0.64^e
	US 5 min	0.79 ± 0.005^gh	10.52 ± 0.021^bc	5.9 ± 0.059^c	2.81 ± 0.034^cd	64.7 ± 0.033^kl	25.2 ± 0.53^cd
	US 10 min	0.72 ± 0.004ⁱ	10.78 ± 0.023^ab	6.0 ± 0.060^bc	2.62 ± 0.031^de	64.5 ± 0.029^m	26.1 ± 0.58^bc
	US 15 min	0.68 ± 0.003^j	10.83 ± 0.025^a	6.3 ± 0.061^ab	2.45 ± 0.029^ef	63.7 ± 0.031^o	27.4 ± 0.61^b
PB1509	BR	0.85 ± 0.07^fg	8.70 ± 0.06^j	3.8 ± 0.71^j	2.56 ± 0.031^e	70.2 ± 0.041^a	0.19 ± 0.032^hj
	Germ. cont.	0.88 ± 0.008^ef	9.38 ± 0.08^hi	4.1 ± 0.07^ij	2.38 ± 0.032^fg	66.8 ± 0.035^e	23.8 ± 0.63^f
	US 5 min	0.73 ± 0.005^hi	9.54 ± 0.012^hi	4.3 ± 0.043ⁱ	2.32 ± 0.028^fg	66.3 ± 0.036^f	25.4 ± 0.54^c
	US 10 min	0.68 ± 0.002^j	9.66 ± 0.011^h	4.5 ± 0.045^hi	2.28 ± 0.027^g	65.7 ± 0.031^g	27.1 ± 0.56^b
	US 15 min	0.62 ± 0.005^k	9.82 ± 0.014^gh	4.8 ± 0.046^gh	2.10 ± 0.025ⁱ	65.0 ± 0.028^ij	29.2 ± 0.58^a
CSR30	BR	0.96 ± 0.06^de	9.90 ± 0.07^g	5.5 ± 0.52^ef	2.41 ± 0.029^f	69.2 ± 0.038^b	0.17 ± 0.023^j
	Germ. cont.	1.09 ± 0.010^bc	10.38 ± 0.12^d	5.8 ± 0.09^d	2.22 ± 0.032^g	65.1 ± 0.034ⁱ	20.3 ± 0.61^gh
	US 5 min	0.88 ± 0.005^ef	10.52 ± 0.022^c	6.1 ± 0.061^bc	2.14 ± 0.025^h	64.7 ± 0.028^kl	21.4 ± 0.54^g
	US 10 min	0.82 ± 0.006^g	10.66 ± 0.021^b	6.60 ± 0.065^a	1.90 ± 0.027^j	63.6 ± 0.024^o	24.8 ± 0.56^de
	US 15 min	0.74 ± 0.007^h	10.51 ± 0.024^cd	6.3 ± 0.063^b	2.05 ± 0.023ⁱ	64.6 ± 0.028^lm	23.1 ± 0.57^fg
PB1637	BR	1.0 ± 0.1^cd	9.40 ± 0.11ⁱ	4.7 ± 0.60^h	3.56 ± 0.043^a	68.6 ± 0.031^d	0.21 ± 0.021^h
	Germ. cont.	1.34 ± 0.013^a	9.78 ± 0.09^h	5.1 ± 0.08^g	2.74 ± 0.034^d	64.9 ± 0.035ⁱ	23.4 ± 0.67^fg
	US 5 min	0.89 ± 0.005^e	9.94 ± 0.016^fg	5.3 ± 0.053^f	2.58 ± 0.031^e	64.7 ± 0.032^k	24.2 ± 0.54^ef
	US 10 min	0.81 ± 0.007^gh	9.96 ± 0.015^f	5.6 ± 0.056^e	2.30 ± 0.023^fg	64.3 ± 0.036ⁿ	25.0 ± 0.56^d
	US 15 min	0.75 ± 0.005^h	10.21 ± 0.021^e	5.90 ± 0.058^cd	2.17 ± 0.026^gh	63.6 ± 0.032^o	27.3 ± 0.53^b

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AsC, ash content; PC, protein content; TDF, total dietary fibre; LC, lipid content; TS, total starch. Means with similar letters in a row for non-basmati and basmati varieties do not differ significantly. The grouping is done in column by the application of Tukey’s test (p < 0.05) where the superscript “a” indicates the highest value among the group. The results are expressed as mean ± standard deviation (n = 3)

Alpha-amylase activity and total starch

Alpha-amylase promotes seed germination and is needed for hydrolysis of starch. In general, alpha-amylase activity fails to occur in dry rice seeds, however, rises rapidly after germination (Guzmán-Ortiz et al. 2019). For BR, the alpha-amylase activity varied from 0.14 to 0.21 U/g, and after germination, a drastic increase from 18.7 to 24.6 U/g was observed. The results were consistent with earlier findings about alpha-amylase synthesis upon germination in BR (Xia et al. 2020). Moreover, ultrasonication further enhanced the alpha-amylase activity and hence the germination capacity of rice. Ultrasound treatment resulted in the highest alpha-amylase activity at 15 min for the PB1121, PB1509, and PB1637 varieties and at 10 min for the PR113, PR121, PR124, PR129, and CSR30 varieties. The highest alpha-amylase activity value of 29.2 U/g was observed for PB1509 US for 15 min. The increase in alpha-amylase activity caused by ultrasonic stimulation during soaking may be associated with a boost in the availability of oxygen and water uptake caused by the changed absorbency and deformation of the outermost layes of cells during ultrasonic cavitation and microstreaming process; documented by López-Ribera and Vicient (2017). They reported that the occurrence of cracks on the outer layer of the grain following ultrasonication ultimately contributed to enhance permeability during the germination process. The variation in alpha-amylase activity in different varieties was probably due to variations in composition and granular structure. Beyond 10 min of ultrasound treatment for PR113, PR121, PR124, PR129, and CSR30 and 15 min for PB1121, PB1509, and PB1637 varieties, the alpha-amylase activity decreased. The possible reason could be that excess ultrasonication treatment might damage the embryo of the grain (Estivi et al. 2022), hence decreasing the alpha-amylase activity of the seed. The TS and alpha-amylase activity for BR, control-germination BR, and ultrasonicated-germinated BR from various varieties are shown in Tables 1 and 2. Compared with that of the BR, a significant reduction in the TS in the control-germinated and ultrasonicated-germinated BR was observed among all varieties. The greatest decrease in TS of 8.6% was observed for the CSR30 US 10 min. The ultrasonication treatment during soaking may have created cracks on the outermost cell wall of the grain, which enhanced the water permeability of the grain, triggering the production of the amylase enzyme and consequently reducing the TS (Chen et al. 2013).

Table 2.

Pasting properties of BR, germinated control BR, ultrasonicated (5, 10 and 15 min) germinated BR from various non-basmati and basmati varieties

Variety	Treatment	PV (cP)	BDV (cP)	FV (cP)	SBV (cP)
Non-basmati
PR113	BR	2132 ± 31^a	157 ± 11^f	4390 ± 9^a	2411 ± 7^bc
	Germ. cont.	1031 ± 12^e	141 ± 10^fg	1882 ± 6^cd	992 ± 6^b
	US 5 min	516 ± 5^kl	128 ± 8^gh	1198 ± 5^fg	810 ± 5^ab
	US 10 min	331 ± 3^m	120 ± 6^h	777 ± 3^ij	566 ± 4^a
	US 15 min	1001 ± 10^f	132 ± 9^g	1622 ± 6^d	753 ± 6^e
PR121	BR	2141 ± 36^b	86 ± 10ⁱ	4370 ± 12^ab	2284 ± 7^cd
	Germ. cont.	1023 ± 11^ef	78 ± 5^ij	1900 ± 7^c	948 ± 7^d
	US 5 min	904 ± 8^gh	72 ± 4^jk	1536 ± 5^de	704 ± 6^fg
	US 10 min	468 ± 5^lm	69 ± 6^k	801 ± 3ⁱ	402 ± 4^f
	US 15 min	776 ± 7^hi	73 ± 4^j	1287 ± 6^f	584 ± 5^g
PR124	BR	1288 ± 26^c	396 ± 20^bc	3462 ± 109	2555 ± 8^c
	Germ. cont.	791 ± 8^h	373 ± 15^c	1501 ± 8^e	1083 ± 6^h
	US 5 min	719 ± 9^ij	368 ± 10^cd	1182 ± 7^g	831 ± 7^gh
	US 10 min	470 ± 6ⁱ	327 ± 9^de	523 ± 4_ij	380 ± 4^de
	US 15 min	532 ± 7^jk	338 ± 11^d	671 ± 6^j	477 ± 5^jk
PR129	BR	2214 ± 46^ab	952 ± 18^a	2491 ± 9^bc	1230 ± 3ⁱ
	Germ. cont.	1109 ± 13^d	583 ± 12^ab	1343 ± 6^ef	817 ± 5^ef
	US 5 min	934 ± 8^g	545 ± 13^b	1150 ± 6^gh	761 ± 6^j
	US 10 min	649 ± 6^j	198 ± 10^ef	830 ± 4^hi	379 ± 4^ij
	US 15 min	737 ± 8ⁱ	282 ± 8^e	1046 ± 8^h	591 ± 5^hi
Basmati
PB1121	BR	1552 ± 33^ab	348 ± 18^c	3726 ± 8^cd	2509 ± 5^bc
	Germ. cont.	954 ± 10^de	316 ± 13^d	1493 ± 6^d	855 ± 4^d
	US 5 min	607 ± 7ⁱ	293 ± 12^de	738 ± 5^j	424 ± 5^g
	US 10 min	579 ± 5^j	211 ± 10^fg	779 ± 7ⁱ	411 ± 3^gh
	US 15 min	435 ± 4^l	139 ± 8^j	579 ± 4^l	283 ± 2^j
PB1509	BR	2017 ± 30^a	571 ± 14^a	4135 ± 3^a	2692 ± 5^a
	Germ. cont.	938 ± 10^e	483 ± 13^ab	1437 ± 5^ef	982 ± 6^c
	US 5 min	707 ± 8^g	351 ± 11^bc	625 ± 6^k	269 ± 4^jk
	US 10 min	637 ± 6^hi	259 ± 9^e	772 ± 3^ij	394 ± 3ⁱ
	US 15 min	481 ± 5^k	196 ± 7^h	422 ± 4^mn	137 ± 2^lm
CSR30	BR	1548 ± 45^b	359 ± 15^b	3819 ± 8^bc	2624 ± 6^b
	Germ. cont.	985 ± 10^cd	331 ± 12^cd	1100 ± 9^gh	441 ± 5^f
	US 5 min	502 ± 7^jk	214 ± 13^f	451 ± 5^m	163 ± 2^l
	US 10 min	391 ± 5^lm	208 ± 10^g	351 ± 4^o	168 ± 3^kl
	US 15 min	456 ± 3^kl	236 ± 9^ef	408 ± 2ⁿ	188 ± 4^k
PB1637	BR	1514 ± 33^bc	195 ± 17^hi	3992 ± 9^b	2662 ± 7^ab
	Germ. cont.	1078 ± 12^c	142 ± 11^ij	1466 ± 8^de	524 ± 6^e
	US 5 min	958 ± 9^d	129 ± 12^jk	1240 ± 6^f	411 ± 5^h
	US 10 min	847 ± 6^f	106 ± 10^k	1168 ± 8^g	427 ± 4^fg
	US 15 min	667 ± 4^h	98 ± 8^l	963 ± 5^h	394 ± 2^ij

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PV, pasting viscosity; BDV, breakdown viscosity; FV, final viscosity; SBV, setback viscosity are viscosities are presented in centi poise (cP). Means with similar letters in a row for non-basmati and basmati varieties do not differ significantly. The grouping is done in column by the application of Tukey’s test (p < 0.05) where the superscript “a” indicates the highest value among the group. The results are expressed as mean ± standard deviation (n = 3)

Pasting properties

Table 2 summarizes the pasting properties of the BR, control-germinated and ultrasonic-germinated BR from all the varieties, and the results are displayed in Fig. 1. Compared with the BR, germination led to a significant decrease in the PV, BDV, FV, and SBV. ANOVA showed that ultrasound and variety had significant effects on the pasting properties of the basmati and non-basmati varieties (Table S2, p < 0.05). Differences in amylase-activity, TS, and protein, ash, lipid, and TDF contents likely contributed to the variation in pasting properties between the BR and germinated flours of all the varieties. The PV, BDV, FV, and SBV of BR ranged from 1288 to 2214 cP, 86 to 952 cP, 3455 to 4386 cP, and 1233 to 2697 cP, respectively, in contrast, the control-germinated BR exhibited lower values, ranging from 791 to 1109 cP (PV), 1100 to 1900 cP (BDV), 78 to 583 cP (FV), and 446 to 1083 cP (SBV). Furthermore, ultrasound treatment further reduced the PV, FV, BDV, and SBV. Paste viscosity and gelatinization characteristics were associated with starch characteristics (Sandhu et al. 2018; Singh et al. 2007). Thus, the rise in alpha-amylase activity and decrease in starch and lipid content during germination may contribute to the lower paste viscosities in ultrasonicated germinated BR as compared to that of control-germinated BR in all varieties. Among the non-basmati varieties, the greatest reduction was observed for PR113 (PV: 84%, BDV: 79%) US treated for 10 min, while among the basmati varieties, PB1509 US treated for 15 min exhibited the greatest reduction in FV (90%) and SBV (94%). He et al. (2022) found comparable variations in pasting properties resulting from germination, a decrease in PV, BDV, FV, and SBV in germinated flour compared to BR flour. The reduction in pasting properties observed in germinated flour could be attributed to the activation of endogenous enzymes, such as α-amylase, β-amylase, limited dextrinase, and α-glucosidases, which breakdown starch into smaller molecules. Compared with those of the control-germinated BR, the PV, BDV, and FV of the ultrasonicated-germinated BR decreased further; similarly, Ding et al. (2018b) reported a lower pasting profile for ultrasonicated-germinated flour than for germinated flour. Furthermore, the PV, FV, BDV, and SBV of non-basmati varieties ultrasonicated for 10 min and basmati varieties ultrasonicated for 15 min (except CSR30) declined the greatest. The decreasing trend of the pasting profile with increasing ultrasonication treatment time was primarily attributed to increasing the enzymatic activity of alpha-amylase and degree of starch hydrolysis, resulting in a reduction in the pasting profile. These significant changes in the pasting profile of germinated BR through ultrasonication offer potential advantages for end-product production. Consequently, the pasting properties of rice flours produced from germinated and ultrasonicated-germinated flour indicated their suitability for specific end-product applications (Ding et al. 2018b).

Fig. 1 — Illustrates pasting profile of BR, germinated BR and ultrasonicated (5, 10 and 15 min) germinated BR

Mineral composition

Table 3 presents the mineral composition of the BR, control-germinated, and ultrasonicated-germinated BR. The minerals are categorized into macro (calcium, phosphorous, potassium, and magnesium) and micro (Iron and zinc) minerals. Germination of rice led to significant changes in the levels of calcium, zinc, phosphorous, potassium, magnesium, and iron contents in the BR from all varieties (Table S3, p < 0.05). Minerals play a crucial role in maintaining and promoting physical well-being by acting as cofactors for enzymatic reactions involved in digestion, assimilation, and absorption processes. The contents of calcium, magnesium, potassium, phosphorous, iron and zinc contents in the BR ranged from 5.11 to 6.52 mg/100 g, 16.4 to 22.45 mg/100 g, 91.4 to 107.5 mg/100 g, 80.5 to 91.91 mg/100 g, 2.51 to 4.83 mg/100 g, and 1.57 to 2.66 mg/100 g, respectively. On the other hand, germinated BR ranged from 6.06 to 7.38 mg/100 g, 17.5 to 23.8 mg/100 g, 93.1 to 109.3 mg/100 g, 82.58 to 95.48 mg/100 g, 3.18 to 5.75 mg/100 g, and 1.64 to 3.04 mg/100 g for calcium, magnesium, potassium, phosphorous, iron and zinc, respectively. The calcium, iron, potassium, and zinc contents increased in the control-germinated BR, while the magnesium content decreased across all varieties. However, as the ultrasonication treatment time increased from 5 to 15 min, a decrease in all the mineral contents, except phosphorus, was observed compared to those of the control-germinated BR for all the varieties. A maximum increase of 9.8% in phosphorus was observed for the CSR30 US 15 min. The trend of decreasing calcium, iron, potassium, Magnesium, and zinc contents with increasing ultrasonication treatment time was mainly related to breakdown of the mineral-binding molecules and enhanced diffusion rate of minerals into the soaking medium due to the development of cracks on the outermost layers of the seed (Xia et al. 2020). The increase in phosphorus content is directly related to the PA content, as phosphorus is predominantly found in the aleurone layer and germ, where PA and its salts account for more than 80% of phosphorous compounds. Phosphorus plays a vital physiological role in humans, as it is involved in carbohydrate metabolism, nucleotide formation, steroid synthesis, and protein lipidation (Majoral 2005).

Table 3.

Mineral composition and phytic acid content profile of BR, germinated control BR, ultrasonicated (5, 10 and 15 min) germinated BR from various non-basmati and basmati varieties

Variety	Treatment	Phytic acid (mg/100 g)	Calcium (mg/100 g)	Iron (mg/100 g)	Potassium (mg/100 g)	Magnesium (mg/100 g)	Phosphorus (mg/100 g)	Zinc (mg/100 g)
Non-basmati
PR113	BR	10.24 ± 0.18^bc	5.11 ± 0.16^j	2.51 ± 0.13ⁱ	99.6 ± 0.28^de	16.4 ± 0.16^ij	81.8 ± 0.28^jk	1.57 ± 0.048^h
	Germ. cont.	4.61 ± 0.08ⁱ	6.06 ± 0.10^de	3.18 ± 0.14^e	103.8 ± 0.17^cd	18.1 ± 0.21^d	82.72 ± 0.14^ij	1.64 ± 0.044^fg
	US 5 min	4.25 ± 0.07^ij	5.75 ± 0.09^fg	3.02 ± 0.15^ef	101.2 ± 0.18^d	17.7 ± 0.22^e	83.92 ± 0.18^hi	1.61 ± 0.032^gh
	US 10 min	4.12 ± 0.09^j	5.71 ± 0.08^g	2.56 ± 0.12^hi	98.4 ± 0.14^ef	17.5 ± 0.19^ef	84.68 ± 0.15^h	1.56 ± 0.035^hi
	US 15 min	3.83 ± 0.01^ab	5.58 ± 0.10^gh	2.43 ± 0.15^j	97.5 ± 0.16^fj	17.2 ± 0.22ⁱ	82.21 ± 0.19^j	1.51 ± 0.031ⁱ
PR121	BR	14.85 ± 0.18^g	5.24 ± 0.17ⁱ	2.9 ± 0.17^fg	107.5 ± 0.21^ab	16.5 ± 0.20^cd	88.7 ± 0.19^ef	1.68 ± 0.038^ef
	Germ. cont.	6.52 ± 0.11^gh	6.16 ± 0.15^cd	3.24 ± 0.18^de	109.3 ± 0.19^a	18.4 ± 0.19^d	89.9 ± 0.18^de	1.71 ± 0.045^e
	US 5 min	6.24 ± 0.13^h	6.02 ± 0.13^e	3.01 ± 0.14^ef	106.4 ± 0.14^b	18.1 ± 0.22^de	90.4 ± 0.17^cd	1.68 ± 0.038^ef
	US 10 min	5.93 ± 0.08^h	5.85 ± 0.11^f	2.83 ± 0.15^fg	105.8 ± 0.15^bc	17.8 ± 0.18^g	90.9 ± 0.19^c	1.65 ± 0.033^f
	US 15 min	5.59 ± 0.012^ai	5.53 ± 0.12^h	2.79 ± 0.11^h	105.1 ± 0.17^c	17.2 ± 0.19^c	90.1 ± 0.14^d	1.62 ± 0.038^g
PR124	BR	15.5 ± 0.12^a	6.12 ± 0.25^d	3.72 ± 0.16^bc	92.7 ± 0.20ⁱ	20.5 ± 0.24^c	89.5 ± 0.22^e	2.37 ± 0.049^bc
	Germ. cont.	8.72 ± 0.014^c	6.84 ± 0.14^a	4.58 ± 0.15^a	93.5 ± 0.11^h	21.8 ± 0.21^a	92.7 ± 0.21^bc	2.94 ± 0.028^a
	US 5 min	8.17 ± 0.13^cd	6.73 ± 0.14^ab	4.22 ± 0.17^ab	93.1 ± 0.15^hi	21.5 ± 0.22^ab	94.3 ± 0.22^ab	2.61 ± 0.27^ab
	US 10 min	7.67 ± 0.14^d	6.61 ± 0.18^b	3.74 ± 0.15^b	92.7 ± 0.12ⁱ	21.1 ± 0.23^b	95.7 ± 0.25^a	2.45 ± 0.024^b
	US 15 min	7.39 ± 0.15^e	6.32 ± 0.14^bc	3.52 ± 0.13^cd	91.2 ± 0.16^j	20.7 ± 0.22^bc	93.2 ± 0.21^b	2.29 ± 0.027^c
PR129	BR	13.94 ± 0.15^b	5.43 ± 0.19^hi	2.91 ± 0.15^f	97.3 ± 0.23^g	16.7 ± 0.19^hi	83.4 ± 0.19ⁱ	1.79 ± 0.035^d
	Germ. cont.	7.42 ± 0.12^de	6.21 ± 0.17^c	3.55 ± 0.17^c	98.9 ± 0.12^e	17.5 ± 0.19^ef	85.3 ± 0.18^gh	1.83 ± 0.015^cd
	US 5 min	7.13 ± 0.08^ef	5.93 ± 0.12^ef	3.28 ± 0.14^d	98.4 ± 0.12^ef	17.3 ± 0.18^f	86.9 ± 0.19^fg	1.79 ± 0.014^cd
	US 10 min	6.96 ± 0.06^f	5.85 ± 0.14^f	2.86 ± 0.11^g	98.1 ± 0.13^f	17.1 ± 0.14^gh	88.2 ± 0.2^f	1.76 ± 0.014^de
	US 15 min	6.58 ± 0.09^fg	5.74 ± 0.12^fg	2.79 ± 0.13^h	96.7 ± 0.14^gh	16.8 ± 0.18^h	85.5 ± 0.17^g	1.68 ± 0.15^ef
Basmati
PB1121	BR	16.18 ± 0.11^a	6.36 ± 0.18^hi	4.83 ± 0.19^ef	91.4 ± 0.15^hi	22.26 ± 0.23^ef	91.91 ± 0.25^ef	2.66 ± 0.041^d
	Germ. cont.	9.70 ± 0.14^c	7.11 ± 0.21^b	5.75 ± 0.14^a	93.1 ± 0.15^ef	23.81 ± 0.24^a	95.48 ± 0.22^d	2.91 ± 0.021^b
	US 5 min	8.92 ± 0.16^e	6.92 ± 0.20^cd	5.68 ± 0.15^b	92.8 ± 0.16^fg	23.4 ± 0.21^ab	97.7 ± 0.21^b	2.78 ± 0.023^bc
	US 10 min	8.31 ± 0.17^f	6.81 ± 0.19^de	5.45 ± 0.18^c	92.5 ± 0.15^g	23.1 ± 0.22^bc	98.2 ± 0.23^ab	2.62 ± 0.024^de
	US 15 min	7.17 ± 0.09^hi	6.69 ± 0.18^f	5.22 ± 0.17^d	90.7 ± 0.18ⁱ	22.5 ± 0.26^d	98.8 ± 0.24^a	2.55 ± 0.02^e
PB1509	BR	9.64 ± 0.16^cd	6.19 ± 0.22^j	3.82 ± 0.12^j	93.7 ± 0.23^de	20.6 ± 0.12^j	80.5 ± 0.19^l	2.27 ± 0.041^j
	Germ. cont.	4.97 ± 0.08^ij	7.1 ± 0.22^b	4.74 ± 0.12^f	95.2 ± 0.14^a	21.85 ± 0.17^g	82.58 ± 0.18^k	2.68 ± 0.027^cd
	US 5 min	4.38 ± 0.07^j	6.98 ± 0.18^bc	4.58 ± 0.15^gh	94.8 ± 0.12^b	21.6 ± 0.14^gh	84.7 ± 0.17^jk	2.52 ± 0.029^f
	US 10 min	3.47 ± 0.04^jk	6.73 ± 0.14^e	4.43 ± 0.12^hi	94.5 ± 0.13^bc	21.3 ± 0.18^h	86.8 ± 0.19ⁱ	2.36 ± 0.019^gh
	US 15 min	3.18 ± 0.05^k	6.62 ± 0.17^gh	4.13 ± 0.15^ij	92.1 ± 0.11^gh	20.8 ± 0.15^hj	87.2 ± 0.14^hi	2.18 ± 0.024ⁱ
CSR30	BR	14.8 ± 0.19^b	5.81 ± 0.18^k	4.15 ± 0.13ⁱ	92.5 ± 0.14^g	21.9 ± 0.19^fg	87.6 ± 0.2^h	2.41 ± 0.039^g
	Germ. cont.	9.41 ± 0.12^d	6.94 ± 0.22^c	5.32 ± 0.14^cd	94.3 ± 0.15^c	23.04 ± 0.22^bc	91.31 ± 0.21^fg	2.92 ± 0.025^ab
	US 5 min	8.73 ± 0.14^ef	6.72 ± 0.21^ef	5.16 ± 0.17^e	93.9 ± 0.12^d	22.8 ± 0.21^c	93.6 ± 0.22^e	2.68 ± 0.24^cd
	US 10 min	8.19 ± 0.11^fg	6.64 ± 0.14^g	4.63 ± 0.15^g	93.5 ± 0.15^e	22.5 ± 0.23^d	95.2 ± 0.23^de	2.47 ± 0.021^fg
	US 15 min	7.58 ± 0.15^gh	6.36 ± 0.18^hi	4.49 ± 0.11^h	91.7 ± 0.12^h	22.1 ± 0.22^f	96.8 ± 0.2^c	2.34 ± 0.19^h
PB1637	BR	14.3 ± 0.12^bc	6.52 ± 0.17^h	4.67 ± 0.12^fg	93.1 ± 0.24^ef	22.45 ± 0.12^de	85.4 ± 0.22^j	2.53 ± 0.036^ef
	Germ. cont.	9.33 ± 0.14^de	7.38 ± 0.24^a	5.72 ± 0.14^ab	95 ± 0.13^ab	23.2 ± 0.24^b	88.52 ± 0.18^gh	3.04 ± 0.024^a
	US 5 min	7.85 ± 0.13^g	7.13 ± 0.25^ab	5.56 ± 0.12^bc	94.8 ± 0.14^b	22.7 ± 0.22^cd	89.4 ± 0.14^g	2.93 ± 0.24^ab
	US 10 min	7.38 ± 0.14^h	6.82 ± 0.21^d	5.32 ± 0.18^cd	94.2 ± 0.18^cd	22.4 ± 0.20^de	91.7 ± 0.17^f	2.77 ± 0.019^c
	US 15 min	5.46 ± 0.16ⁱ	6.74 ± 0.22^e	5.19 ± 0.17^de	92.9 ± 0.12^f	21.8 ± 0.21^g	93.6 ± 0.19^e	2.63 ± 0.018^ij

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The results are expressed as mean ± standard deviation (n = 3). Means with similar letters in a row for non-basmati and basmati varieties do not differ significantly. The grouping is done in column by the application of Tukey’s test (p < 0.05) where the superscript “a” indicates the highest value among the groups. The results are expressed as mean ± standard deviation (n = 3)

Phytic acid

The PA content of BR, control-germinated, and ultrasonicated-germinated BR from different rice varieties are presented in Table 3. PA mainly accumulates in the aleurone layer of grains. It has been linked to a mineral-related deficit in humans and also affects protein and fat availability (Su et al. 2014). A decline in PA during germination might improve the accessibility of some nutrients. After germination, each variety showed decreasing PA content. The contents of PA in BR and control germinated BR flour ranged from 9.6 to 16.1 and 4.6 to 9.3 mg/kg, respectively. Cornejo et al. (2015) reported that the PA content decreased by 80% after 96 h of germination in BR. During the soaking step in the germination process, phytase enzymes are activated inside the seed and start degrading PA. Changes in phytase activity have been analyzed in several cereals, and the results showed that the PA content decreased during germination (Guzmán-Ortiz et al. 2019). Ultrasonication treatment further reduced the PA content during germination. A lower PA content was observed in the ultrasonicated germinated BR than in the other BR for all varieties. The greatest decrease of 67% in PA was recorded for PB1121 US at 15 min. Interestingly, a statistical analysis (ANOVA) of germination and ultrasonication pretreatment (Table S3) revealed a significant interaction between the two treatments and showed the synergistic impact of the two treatments on PA (p < 0.05). It is evident that the acoustic effect of cavitation induces disintegration of surface material and accelerates the activity of the phytase enzyme and hence the breakdown of PA and other complex compounds, such as inositol hexa-phosphate, which were responsible for the reduction in PA during germination (Banura and Singh 2023). Mohammadi et al. (2021) reported that ultrasonicated rice bran samples (UWA, UWN, and UWB) had 11–23% less PA than soaked rice bran samples (SWA, SWN, and UWB). This highlighted the predominant effect of ultrasound in the reduction of PA.

Sugar profile by IC

Ion exchange chromatography (IC) detected the presence of inositol, glucose, fructose, xylose, sucrose, maltose, and raffinose sugars and tabulated in Table 4. Statistical analysis via ANOVA revealed that variety and ultrasonication treatment significantly influenced the sugar profile. Interestingly, the F value showed that the synergistic effect of ultrasonication and germination treatment had a more prominent effect than that of the other treatments (Table S4). The contents of inositol, glucose, fructose, xylose, sucrose, maltose, and raffinose in the control group varied from 145 to 235 mg/kg, 970 to 1146 mg/kg, 418 to 508 mg/kg, 575 to 708 mg/kg, 3503 to 4829 mg/kg, 312 to 442 mg/kg and 112 to 209 mg/kg, respectively, and those in the control BR varied from 323 to 407 mg/kg, 621 to 758 mg/kg, 352 to 423 mg/kg, 575 to 708 mg/kg, 2932 to 4314 mg/kg, 217 to 289 mg/kg and 253 to 384 mg/kg, respectively. The glucose, fructose, sucrose, and maltose contents of the control germinated BR increased, and the xylose, inositol, and raffinose contents decreased compared to those of the BR counterpart in all varieties. These changes could be attributed to the utilization of starch as a source of energy during germination by alpha-amylase, beta-amylase and other debranching enzymes, which resulted in the hydrolysis of starch into simpler compounds such as glucose, maltose, fructose and other monosaccharides (Oliveira et al. 2022). Sibian et al. (2017) also reported that the total sugars in wheat, triticale and BR increased by 43%, 58% and 44%, respectively, after germination. Moreover, ultrasonication treatment further significantly increased the glucose, fructose, maltose, and sucrose contents, whereas the xylose, inositol, and raffinose contents significantly decreased. The maximum increase in glucose (128%) and maltose (97%) contents was observed for PB1637 US 15 min and PB1121 US 15 min, respectively, whereas the maximum decreased in inositol (83%) was observed for CSR30 US10 min. Ultrasound treatment intensified the starch degradation by breaking starch-protein and starch-lipid complexes, thereby increasing the substrate’s susceptibility to alpha-amylase enzymes, which accelerated starch hydrolysis and contributed to higher formation of total sugar upon germination (Xia et al. 2020). Higher alpha-amylase activity was detected in the ultrasonicated germinated BR in this study. During germination, alpha-amylase digests complex starch into glucose or dextrin, which is then hydrolyzed to yield reducing sugars such as glucose, fructose, and maltose (Ding et al. 2018a). Ding et al. (2018a), also reported an increase in the sugar content in ultrasonicated germinated rice and red rice compared to that in control germinated rice. A maximum decreased in the raffinose (89%) and xylose (27%) contents were observed for the PR113 US 10 min and PB1637 US 15 min, respectively. The decline in raffinose content upon germination has been linked to the activity of alpha-galactosidase, which breaks down α-(1,6)-linkages, thereby elevating the overall soluble sugar level and lowering the raffinose concentration (Martín-Cabrejas et al. 2008). The different concentrations observed for the different varieties could be due to the differences in grain genotypes that influence the enzyme pattern and the degradation processes of the seed tissues.

Table 4.

Sugar profile of BR, germinated control BR, ultrasonicated (5, 10 and 15 min) germinated BR from various non-basmati and basmati varieties

Variety	Treatment	Inositol (mg/kg)	Glucose (mg/kg)	Fructose (mg/kg)	Xylose (mg/kg)	Sucrose (mg/kg)	Raffinose (mg/kg)	Maltose (mg/kg)
Non-basmati
PR113	BR	323 ± 3.7^bc	655 ± 8^j	423 ± 3^g	628 ± 11^ab	4315 ± 15^g	337 ± 4.8^ab	274 ± 2.7^ij
	Germ. cont.	145 ± 2.3^h	970 ± 5^gh	508 ± 4^b	562 ± 7^de	4599 ± 11^fg	159 ± 2.1^de	366 ± 1.3^g
	US 5 min	131 ± 3.4ⁱ	1134 ± 7^e	518 ± 6^ab	524 ± 6^f	4858 ± 8^d	46 ± 1.2^jk	388 ± 1.2^ef
	US 10 min	98 ± 2.1^j	1359 ± 8^ab	532 ± 8^a	481 ± 7ⁱ	5125 ± 12^b	37 ± 1.4^k	421 ± 1.8^cd
	US 15 min	140 ± 3.6^hi	1010 ± 4^f	502 ± 3^bc	554 ± 9^e	4782 ± 9^ef	62 ± 1.5^j	377 ± 1.3^fg
PR121	BR	338 ± 4.2^b	684 ± 5^ij	392 ± 8ⁱ	575 ± 10^d	3981 ± 10^gh	279 ± 3.6^bc	280 ± 3.5ⁱ
	Germ. cont.	209 ± 3.2^d	991 ± 5^g	464 ± 4^cd	506 ± 6^fg	4664 ± 12^f	142 ± 2.4^fg	383 ± 2.1^f
	US 5 min	185 ± 2.6^ef	1167 ± 7^cd	470 ± 6^c	486 ± 4^h	5496 ± 11^ab	125 ± 2.6^h	394 ± 1.9^e
	US 10 min	108 ± 3.8^ij	1352 ± 9^b	502 ± 7^bc	431 ± 5^j	5638 ± 14^a	70 ± 1.9ⁱ	423 ± 2.3^c
	US 15 min	164 ± 2.8^g	887 ± 7^hi	453 ± 4^d	494 ± 5^gh	4855 ± 10^de	62 ± 1.7^ij	400 ± 1.8^d
PR124	BR	373 ± 4.6^a	621 ± 5^k	364 ± 7^j	708 ± 7^a	2933 ± 9^k	385 ± 4.9^a	257 ± 2.6^k
	Germ. cont.	236 ± 3.6^c	1008 ± 9^fg	428 ± 4^f	624 ± 4^b	3504 ± 13^ij	209 ± 2.3^cd	313 ± 2.1^hi
	US 5 min	208 ± 2.4^de	1160 ± 6^d	436 ± 5^ef	581 ± 7^cd	3537 ± 12ⁱ	140 ± 2.4^g	351 ± 2.2^gh
	US 10 min	182 ± 2.1^f	1269 ± 8^c	440 ± 3^de	542 ± 5^ef	3607 ± 14^hi	121 ± 1.9^hi	396 ± 1.9^de
	US 15 min	224 ± 3.6^cd	925 ± 9^h	425 ± 4^fg	596 ± 3^bc	3407 ± 12^j	142 ± 2.3^f	345 ± 1.8^h
PR129	BR	361 ± 4.3^ab	721 ± 7ⁱ	376 ± 7^ij	582 ± 7^c	3904 ± 11^h	324 ± 4.3^b	273 ± 3.8^j
	Germ. cont.	207 ± 3.2^e	1146 ± 7^de	418 ± 6^h	498 ± 5^g	4829 ± 15^e	161 ± 2.5^d	443 ± 2.3^bc
	US 5 min	182 ± 2.6^fg	1281 ± 6^bc	406 ± 4^hi	452 ± 6^ij	4898 ± 13^cd	151 ± 2.7^e	448 ± 2.1^ab
	US 10 min	163 ± 2.4^gh	1457 ± 7^a	439 ± 3^e	427 ± 4^k	4959 ± 15^be	133 ± 2.3^gh	453 ± 2.4^a
	US 15 min	185 ± 2.1^ef	1022 ± 9^ef	423 ± 6^hi	481 ± 3^hi	4929 ± 12^c	145 ± 2.6^ef	443 ± 2.2^b
Basmati
PB1121	BR	396 ± 4.1^ab	677 ± 6^mn	353 ± 8^k	638 ± 7^ab	3228 ± 10^l	284 ± 2.8^c	217 ± 1.9^k
	Germ. cont.	204 ± 2.5^de	1026 ± 8^j	420 ± 5^gh	556 ± 5^cd	4026 ± 11ⁱ	118 ± 1.9ⁱ	394 ± 1.9^de
	US 5 min	180 ± 2.1^f	1138 ± 7^g	423 ± 4^g	529 ± 4^f	4105 ± 12^h	97 ± 1.6^j	399 ± 1.7^cd
	US 10 min	185 ± 2.5^ef	1375 ± 6^c	425 ± 6^f	491 ± 7^hi	4144 ± 14^h	85 ± 1.3^k	426 ± 2.4^bc
	US 15 min	158 ± 1.8^hi	1502 ± 9^b	433 ± 4^ef	463 ± 5^kl	4256 ± 13^gh	74 ± 1.2^l	430 ± 2.2^ab
PB1509	BR	367 ± 3.9^c	759 ± 9^l	386 ± ^6hi	628 ± 9^b	3698 ± 9^k	254 ± 3.2^d	289 ± 2.4ⁱ
	Germ. cont.	195 ± 2.5^e	1098 ± 7^h	451 ± 5^c	542 ± 4^de	4336 ± 13^g	113 ± 2.4ⁱ	422 ± 1.8^c
	US 5 min	174 ± 2.9^g	1182 ± 8^f	458 ± 3^hi	526 ± 3^fg	4375 ± 12^fg	88 ± 2.6^k	430 ± 2.3^ab
	US 10 min	179 ± 2.1^fg	1326 ± 5^d	455 ± 3^c	496 ± 5^h	4408 ± 14^f	67 ± 1.1^l	429 ± 2.2^b
	US 15 min	169 ± 3.2^h	1673 ± 12^a	470 ± 2^a	461 ± 6^l	4521 ± 12^e	34 ± 1.2^m	437 ± 2.7^a
CSR30	BR	383 ± 4.2^b	683 ± 5^m	358 ± 9^j	656 ± 6^a	3719 ± 12^j	354 ± 3.9^a	228 ± 2.1^ij
	Germ. cont.	169 ± 2.3^gh	1067 ± 4^hi	443 ± 4^de	566 ± 7^c	4551 ± 13^de	172 ± 2.3^e	368 ± 1.9^gh
	US 5 min	128 ± 2.1^j	1270 ± 12^e	447 ± 3^d	533 ± 8^ef	4644 ± 14^d	159 ± 2.4^fg	376 ± 1.7^f
	US 10 min	65 ± 1.2^l	1375 ± 14^c	455 ± 2^b	516 ± 5^g	4773 ± 13^bc	142 ± 2.7^h	381 ± 2.1^e
	US 15 min	121 ± 2.3^k	1051 ± 9^ij	436 ± 4^e	552 ± 4^d	4673 ± 15^cd	166 ± 2.1^e	398 ± 2.3^cd
PB1637	BR	407 ± 3.8^a	643 ± 6ⁿ	394 ± 4^h	620 ± 7^b	3795 ± 11^ij	339 ± 4.7^b	226 ± 2.2^j
	Germ. cont.	214 ± 1.6^d	995 ± 7^jk	447 ± 5^cd	537 ± 6^e	4770 ± 13^c	164 ± 1.9^ef	342 ± 2.4^h
	US 5 min	174 ± 2.3^g	1194 ± 11^f	452 ± 3^bc	511 ± 4^gh	4798 ± 12^b	152 ± 2.2^g	369 ± 2.3^g
	US 10 min	140 ± 2.4ⁱ	1264 ± 12^e	458 ± 2^ab	481 ± 3^k	4883 ± 14^a	118 ± 1.7ⁱ	372 ± 2.1^fg
	US 15 min	109 ± 2.1^kl	1472 ± 14^b	470 ± 5^a	453 ± 4^m	4921 ± 11^a	102 ± 1.4^j	377 ± 2.2^ef

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The results are expressed as mean ± standard deviation (n = 3). Means with similar letters in a row for basmati and non-basmati varieties do not differ significantly. The grouping is done in column by the application of Tukey’s test (p < 0.05) where the superscript “a” indicates the highest value among the group. The results are expressed as mean ± standard deviation (n = 3)

Polyphenolic profile by HPLC

Presence of six phenolic compounds, namely, ferulic acid, gallic acid, vanillic acid, p-coumaric acid, and 4-hydroxybenzoic acid, in both the free and bound forms recorded and analyzed by HPLC (Table 5). Gallic acid was found in its free form, while 4-hydroxybenzoic acid and vanillic acid were detected in their bound forms. ANOVA revealed that the phenolic acid content was significantly affected by variety and ultrasonication. The F value displayed that ultrasonication had a more significant effect than the other varieties on the contents of bound gallic and free p-coumaric, 4-hydroxybenzoic, and vanillic acid (Table S5). Ferulic acid and p-coumaric acid were present in both bound and free forms in all varieties. Germination induced changes in the phenolic acid compounds present in both the bound and free forms. A greater accumulation of polyphenolic compounds in the ultrasonicated-germinated BR of all varieties was observed. The levels of bound and free ferulic acid, p-coumaric acid, and vanillic acid increased in the control-germinated BR for all varieties, with a further substantial increase observed in the ultrasonicated-germinated BR. Ferulic acid and p-coumaric acid were identified as the predominant phenolic compounds present in rice (Mudgal and Singh 2022). Among the non-basmati varieties, the maximum increase of 15% (72.6 mg/kg) in bound ferulic acid was observed for the PR121 US 10 min, while among the basmati varieties, the maximum increase of 12% (83.4 mg/kg) was observed for the PB1509 US 15 min. The free gallic acid content in germinated BR was lower than that in BR, but it increased by 16.8% after ultrasound treatment (US 10 min) for PR129 among non-basmati varieties and by 47% after ultrasound treatment (US 15 min) for PB1637 among basmati varieties. The bound gallic acid gradually increased from trace amounts to 76% with ultrasonication treatment. The contents of bound 4-hydroxybenzoic acid maximum decreased by 72%, while free forms maximum increased by 380%, when all varieties underwent US 5 to US 15 min of treatment. This observation could be attributed to the disintegration of the cell wall structures of the seeds during ultrasonication, which liberates free polyphenols. During germination, bound phenolics were broken down and converted into free phenolics. Phenolic acids can also be generated from other types of phenolic acids or amino acids using the shikimate route, which is regulated by the shikimic enzyme. It is also known that the enzymatic hydrolysis and breakdown of seed cell wall components during germination in legumes, pseudocereals, and cereals causes a rise in free phenolics (Bhinder et al. 2021). The further increase in phenolic compounds after ultrasonication treatment may be caused by the cavitation of ultrasonic waves disturbing the outer structure of the cell components and facilitating the exchange of substances from the seed cells. This effect accelerates the seed hydration process and promotes cell division, resulting in an increase in phenolic compounds (Estivi et al. 2022).

Table 5.

Phenolic compounds (in mg/kg dw) of BR, germinated control BR, ultrasonicated (5, 10 and 15 min) germinated BR from various non-basmati and basmati varieties

Non-basmati
	PR113					PR121					PR124					PR129
	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min
Fer
Bound	83 ± 2^cd	87.5 ± 0.62^bc	92.31 ± 0.75^ab	94.7 ± 0.84^a	90.5 ± 0.77^b	63 ± 2^k	66.2 ± 0.48^j	68.5 ± 0.51^hi	72.6 ± 0.55^gh	67.2 ± 0.58^ij	73.2 ± 3^g	78.1 ± 0.61^ef	81.73 ± 0.62^de	83.8 ± 0.6^c	79.4 ± 0.64^e	72 ± 2^h	76.8 ± 0.62^fg	79.2 ± 0.65^e	81.9 ± 0.62^d	77.37 ± 0.66^f
Free	3 ± 0.3^g	4.5 ± 0.14^bc	6.37 ± 0.25^ab	6.85 ± 0.23^a	5.29 ± 0.19^b	1.2 ± 0.23^h	2.6 ± 0.17^gh	3.1 ± 0.19^fg	3.5 ± 0.14^ef	3.3 ± 0.15^f	3 ± 0.49^g	3.8 ± 0.13^e	4 ± 0.14^d	4.3 ± 0.15^c	3.8 ± 0.17^e	3 ± 0.38^g	3.9 ± 0.13^de	4.3 ± 0.14^c	4.5 ± 0.12^bc	4.1 ± 0.15^cd
Total	86 ± 2.3^d	92 ± 0.76^bc	98 ± 1^ab	102 ± 1.07^a	96 ± 0.96^b	64 ± 2.23^k	68.8 ± 0.65^ij	71.6 ± 0.7^hi	76 ± 0.69^gh	70 ± 0.73ⁱ	76 ± 3.49^g	81 ± 0.74^ef	85. 0.0.76^de	88 ± 0.75^c	83 ± 0.81^e	75 ± 2.38^h	80 ± 0.75^fg	83 ± 0.79^e	86 ± 0.74^cd	81. ± 0.81^f
Gal
Bound	N.D	0.21 ± 0.019^g	0.26 ± 0.021^fg	0.39 ± 0.025^cd	0.31 ± 0.024^ef	N.D	T.r	0.34 ± 0.028^de	0.41 ± 0.032^c	0.37 ± 0.028^d	N.D	0.47 ± 0.03^bc	0.53 ± 0.036^ab	0.57 ± 0.037^a	0.51 ± 0.038^b	N.D	0.21 ± 0.024^g	0.29 ± 0.021^f	0.37 ± 0.028^d	0.32 ± 0.027^e
Free	1 ± 028^e	0.97 ± 0.11^ef	1.14 ± 0.14^d	1.19 ± 0.015^c	1.12 ± 0.012^de	0.68 ± 0.14^ij	0.68 ± 0.009^j	0.69 ± 0.008^hi	0.73 ± 0.006^h	0.69 ± 0.01ⁱ	1.24 ± 0.25^bc	1.17 ± 0.012^cd	1.25 ± 0.017^b	1.31 ± 0.019^a	1.27 ± 0.014^ab	0.83 ± 0.09^g	0.81 ± 0.009^gh	0.93 ± 0.011^f	0.97 ± 0.013^ef	0.92 ± 0.014^fg
Total	1 ± 0.28^hi	1.18 ± 0.03^f	1.4 ± 0.035^d	1.58 ± 0.04^c	1.43 ± 0.036^cd	0.68 ± 0.14^ij	0.68 ± 0.009^j	1.03 ± 0.036^gh	1.14 ± 0.038^fg	1.06 ± 0.038^g	1.24 ± 0 .25^e	1.64 ± 0.047^bc	1.78 ± 0.053^ab	1.88 ± 0.056^a	1.78 ± 0.052^b	0.83 ± 0.09ⁱ	1.02 ± 0.033^h	1.22 ± 0.032^ef	1.34 ± 0.041^de	1.24 ± 0.041^e
T-fer
Bound	23.8 ± 1.07^ab	24.5 ± 0.24^a	20.2 ± 0.21^d	17.8 ± 0.19^e	22.1 ± 0.22^bc	3.3 ± 0.42^h	3.8 ± 0.04^g	3.1 ± 0.05ⁱ	2.7 ± 0.03^j	3.4 ± 0.06^gh	4.3 ± 0.2^fg	4.5 ± 0.07^f	3.9 ± 0.08^g	3 ± 0.04^ij	3.2 ± 0.05^hi	21.5 ± 1.09^cd	22.6 ± 0.27^b	19.4 ± 0.17^de	16.3 ± 0.21^ef	21.8 ± 0.26^c
Free	N.D	4.1 ± 0.04^bc	4.8 ± 0.03^b	5.6 ± 0.05^a	3.5 ± 0.02^d	N.D	T.r	1.3 ± 0.01^fg	2.5 ± 0.02^de	1.2 ± .01^g	N.D	T.r	1.5 ± 0.03^f	2.1 ± 0.02^e	1.9 ± .01^ef	N.D	T.r	3.6 ± 0.04^cd	5.2 ± 0.06^ab	3.8 ± 0.03^c
Total	23.8 ± 1.07^c	28.6 ± 0.28^a	25 ± 0.24^bc	23.4 ± 0.24^cd	25.6 ± 0.24^ab	3.3 ± 0.42^j	3.8 ± 0.04ⁱ	4.4 ± 0.06^h	5.2 ± 0.05^f	4.6 ± .07^g	4.3 ± 0.2^hi	4.5 ± 0.07^gh	5.4 ± 0.11^ef	5.1 ± 0.06^fg	5.1 ± .06^fg	21.5 ± 1.09^e	22.6 ± 0.27^de	23 ± 0.21^d	21.5 ± 0.27^e	25.6 ± 0.29^b
p-cou
Bound	25 ± 1.01^e	29.32 ± 0.19^bc	31.6 ± 0.23^ab	33.5 ± 0.24^a	30.1 ± 0.23^b	12.6 ± 0.63^k	20.24 ± 0.17^ij	21.8 ± 0.18^hi	22.5 ± 0.21^gh	21.3 ± 0.23ⁱ	15 ± 0.97^jk	23.4 ± 0.24^g	24.5 ± 0.23^f	24.9 ± 0.24^ef	24.3 ± 0.26^fg	19 ± 0.66^j	25.18 ± 0.27^de	25.8 ± 0.23^d	26.5 ± 0.24^c	26.1 ± 0.25^cd
Free	2 ± 0.1^de	2.7 ± 0.027^bc	3.1 ± 0.034^ab	3.4 ± 0.031^a	2.8 ± 0.024^b	0.97 ± 0.09^fg	2.2 ± 0.021^cd	2.8 ± 0.024^b	3.1 ± 0.032^ab	2.6 ± 0.028^c	0.93 ± 0.01^g	2.5 ± 0.028^cd	2.8 ± 0.021^b	3.4 ± 0.024^a	2.7 ± 0.021^bc	0.78 ± 0.03^h	1.53 ± 0.015^f	1.9 ± 0.018^e	2.1 ± 0.023^d	1.6 ± 0.011^ef
Total	27 ± 1.11^e	32.02 ± 0.21^bc	34.7 ± 0.26^ab	36.9 ± 0.21^a	32.9 ± 0.21^b	13.57 ± 0.21ⁱ	22.44 ± 0.21^h	24.6 ± 0.217^g	25.6 ± 0.21^fg	23.9 ± 0.25^gh	15.93 ± 0.28ⁱ	25.9 ± 0.26^f	27.3 ± 0.25^de	28.3 ± 0.26^cd	27 ± 0.28^e	19.78 ± 0.3^hi	26.71 ± 0.28^ef	27.7 ± 0.24^d	28.6 ± 0.26^c	27.7 ± 0.26^d
4-hba
Bound	0.64 ± 0.04^c	0.61 ± 0.024^d	0.58 ± 0.024^de	0.53 ± 0.021^e	0.61 ± 0.022^d	0.33 ± 0.04^ef	0.3 ± 0.015^f	0.27 ± 0.013^g	0.25 ± 0.016	0.28 ± .018	0.75 ± 0.06^a	0.73 ± 0.024^ab	0.68 ± 0.023^b	0.65 ± 0.023^bc	0.62 ± .023^bc	0.28 ± 0.09^fg	0.25 ± 0.011^gh	0.21 ± 0.014^hi	0.19 ± 0.01^j	0.23 ± 0.016^h
Free	N.D	0.9 ± 0.02^de	1.2 ± 0.04^cd	1.7 ± 0.06^bc	1.1 ± 0.03^d	N.D	Tr	0.4 ± 0.01^f	0.9 ± 0.01^de	0.7 ± 0.02^e	N.D	1.5 ± 0.05^c	1.9 ± 0.03^b	2.5 ± 0.05^a	2.1 ± 0.04^ab	N.D	Tr	0.2 ± 0.01^g	0.5 ± 0.02^ef	Tr
Total	0.64 ± 0.04^g	1.51 ± 0.04^d	1.78 ± 0.06^c	2.23 ± 0.27^bc	1.71 ± 0.25^cd	0.33 ± 0.04^h	0.3 ± 0.01^h	0.67 ± 0.02^fg	1.15 ± 0.02^de	0.98 ± 0.03^e	0.75 ± 0.06^ef	2.23 ± 0.07^bc	2.58 ± 0.05^b	3.15 ± 0.07^a	2.72 ± 0.06^ab	0.28 ± 0.09^hi	0.25 ± 0.01ⁱ	0.41 ± 0.02^gh	0.69 ± 0.03^f	0.23 ± 0.01^ij
Van
Free	40.5 ± 0.8^c	42.1 ± 0.36^bc	43.6 ± 0.34^ab	44.2 ± 0.32^a	43.1 ± 0.34^b	11.9 ± 0.82^j	13.7 ± 0.21ⁱ	14.8 ± 0.23^gh	15.6 ± 0.24^f	14.5 ± 0.25^h	15.5 ± 0.56^fg	16.1 ± 0.26^e	16.9 ± 0.24^d	17.6 ± 0.25^cd	16.5 ± 0.26^de	12.6 ± 0.35^ij	14.1 ± 0.22^hi	15.9 ± 0.23^ef	16.5 ± 0.24^de	15.1 ± 0.23^g
Bound	N.D	0.31 ± 0.019^bc	0.34 ± 0.021^ab	0.37 ± 0.023^a	0.32 ± 0.024^b	N.D	0.12 ± 0.008^g	0.18 ± 0.015^de	0.22 ± 0.018^c	0.16 ± 0.019^f	N.D	0.17 ± 0.017^e	0.19 ± 0.019^d	022 ± 0.02^c	0.17 ± 0.017^e	N.D	0.13 ± 0.014^fg	0.19 ± 0.015^d	0.21 ± 0.021^cd	0.16 ± 0.018^f
Total	40.5 ± 0.8^c	42.4 ± 0.37^bc	43.9 ± 0.36^ab	44.5 ± 0.34^a	43.4 ± 0.36^b	11.9 ± 0.82^jk	13.9 ± 0.21^ij	15.0 ± 0.24^g	15.8 ± 0.25^ef	14.7 ± 0.26^hi	15.5 ± 0.56^g	16.3 ± 0.27^ef	17.1 ± 0.25^d	17.8 ± 0.27^cd	16.7 ± 0.27^e	12.6 ± 0.35^j	14.3 ± 0.23ⁱ	16.1 ± 0.24^f	16.7 ± 0.26^de	15.3 ± 0.24^gh

Basmati
	PR1121					PB1509						CSR30						PB1637
	BR	Germ cont	US 5 min	US 10 min	US 15 min	BR	Germ cont	US 5 min	US 10 min	US 15 min	BR	Germ cont	US 5 min	US 10 min	US 15 min	BR	Germ cont	US 5 min	US 10 min	US 15 min
Fer
Bound	135.5 ± 1.6^c	140.7 ± 0.84^bc	141.7 ± 0.82^b	143.1 ± 0.73^ab	145.4 ± 0.79^a	74 ± 2.0^l	79.8 ± 0.52^kl	81.2 ± 0.51^k	83.4 ± 0.6^jk	84.8 ± 0.58^j	107 ± 2.5^f	112.6 ± 0.95^ef	115.3 ± 0.87	118.9 ± 0.91^d	113.2 ± 0.94^e	91 ± 2.8ⁱ	95.7 ± 0.81^h	96.3 ± 0.75^gh	98.1 ± 0.77^gh	91 ± 0.75^g
Free	6 ± 0.57^e	6.8 ± 0.26^d	7.1 ± 0.27^c	7.4 ± 0.24^ab	7.5 ± 0.26^a	1.1 ± 0.2^j	2.1 ± 0.14^hi	2.7 ± 0.12^h	3.1 ± 0.18^gh	3.4 ± 0.19^g	6 ± 0.4^e	6.4 ± 0.24^de	6.9 ± 0.25^cd	7.2 ± 0.21^dc	7.3 ± 0.25^b	2 ± 0.4ⁱ	3.4 ± 0.17^g	3.8 ± 0.15^fg	4.1 ± 0.16^f	4.4 ± 0.14^ef
Total	141 ± 2.17^c	147 ± 1.1^bc	148 ± 1.09^b	150 ± 0.97^ab	152 ± 1.05^a	75 ± 2.2^l	81.9 ± 0.66^kl	83.9 ± 0.63^k	86.5 ± 0.78^ik	88.2 ± 0.77ⁱ	113 ± 2.9^ef	119 ± 1.19^e	122 ± 1.12^d	126 ± 1.12^cd	120 ± 1.19^de	93 ± 3.2^hi	99 ± 0.98^h	100 ± 0.9^gh	102 ± 0.93^g	104 ± 0.89^f
Gal
Bound	N.D	0.69 ± 0.038^b	0.72 ± 0.037^ab	0.75 ± 0.04^a	0.76 ± 0.041^a	N.D	0.28 ± 0.024^fg	0.37 ± 0.027^ef	0.43 ± 0.029^e	0.45 ± 0.031^de	N.D	0.56 ± 0.033^d	0.59 ± 0.034^c	0.64 ± 0.038^cd	0.57 ± 0.027^cd	N.D	0.18 ± 0.019^h	0.22 ± 0.021^gh	0.25 ± 0.023^g	0.31 ± 0.024^f
Free	3.8 ± 0.38^c	3.3 ± 0.024^d	3.9 ± 0.026^b	4.2 ± 0.027^ab	4.5 ± 0.029^a	0.87 ± 011^k	0.85 ± 0.008^l	0.92 ± 0.01^jk	0.95 ± 0.009^j	0.96 ± 0.012^ij	3 ± 02^de	2.8 ± 0.19^e	3.3 ± 0.023^d	3.9 ± 0.024^bc	3.5 ± 0.025^cd	1.7 ± 02^gh	1.5 ± 0.017ⁱ	1.9 ± 0.019^g	2.3 ± 0.021^fg	2.5 ± 0.023_ef
Total	3.8 ± 0.38^d	3.99 ± 0.062^cd	4.62 ± 0.063^b	4.95 ± 0.06^b	5.26 ± 0.07^a	0.87 ± 0.11^l	1.13 ± 0.032^k	1.29 ± 0.03^jk	1.38 ± 0.038^j	1.41 ± 0.043^hj	3.0 ± 0.2^e	3.36 ± 0.052^de	3.89 ± 0.057^d	4.54 ± 0.062^bc	4.07 ± 0.052^c	1.7 ± 0.2^gh	1.68 ± 0.036^h	2.12 ± 0.04^h	2.55 ± 0.04^f	2.81 ± 0.05^ef
t-fer
Bound	4.5 ± 0.36^f	4.9 ± 0.07^ef	4.1 ± 0.8^fg	3.8 ± 0.09^g	3.3 ± 0.06^h	7.5 ± 0.57^d	8.9 ± 0.1^bc	7.6 ± 0.09^cd	6.8 ± 0.07^de	6.1 ± 0.08^e	2.9 ± 0.09^hi	3.3 ± 0.04^h	2.6 ± 0.02ⁱ	2.4 ± 0.3^j	3.7 ± 0.04^gh	10 ± 0.8^ab	11.5 ± 0.28^a	9.8 ± 0.11^b	8.3 ± 0.14^c	11.1 ± 0.16^a
Free	N.D	T.r	1.3 ± 0.01ⁱ	1.8 ± 0.02^e	2.2 ± 0.03^e	N.D	T.r	1.7 ± 0.04^h	2.3 ± 0.05^d	2.6 ± 0.04^b	N.D	T.r	0.9 ± 0.01^k	1.2 ± 0.02^j	1.8 ± 0.03^g	N.D	T.r	2.1 ± 0.04^f	2.5 ± 0.05^c	3.2 ± 0.07^a
Total	4.5 ± 0.36^hi	4.9 ± 0.07^h	5.4 ± 0.81^gh	5.6 ± 0.11^fg	5.5 ± 0.09^g	7.5 ± 0.57^f	8.9 ± 0.1^e	9.3 ± 0.13^d	9.1 ± 0.12^de	8.7 ± 0.12^ef	2.9 ± 0.09^k	3.3 ± 0.04^j	3.5 ± 0.03^ij	3.6 ± 0.32ⁱ	5.5 ± 0.07^g	10 ± 0.8^cd	11.5 ± 0.28^bc	11.9 ± 0.15^b	10.8 ± 0.19^c	14.3 ± 0.23^a
P-cou
Bound	53 ± 0.68^e	69.4 ± 0.36^bc	71.8 ± 0.38^b	72.5 ± 0.37^ab	73.1 ± 0.38^a	21 ± 0.89^k	35.74 ± 0.28^h	36.4 ± 0.29^gh	36.9 ± 0.24^gh	37.5 ± 0.25^g	46 ± 0.03^fg	63.81 ± 0.34^d	64.8 ± 0.36^cd	65.5 ± 0.37^c	64.2 ± 0.38^cd	34 ± 0.65^j	51.3 ± 0.31^f	52.7 ± 0.34^ef	53.5 ± 0.35^de	53.8 ± 0.37^de
Free	2 ± 0.07^j	3.1 ± 0.028^g	3.3 ± 0.024^fg	3.6 ± 0.027^e	3.7 ± 0.029^de	2 ± 0.07^j	2.6 ± 0.024ⁱ	2.7 ± 0.023^hi	3.1 ± 0.28^g	3.4 ± 0.026^f	3 ± 0.14^h	3.8 ± 0.027^c	4.1 ± 0.031^b	4.5 ± 0.032^a	3.9 ± 0.024^bc	3 ± 0.14^h	3.5 ± 0.026^ef	3.7 ± 0.028^cd	4.1 ± 0.031^b	4.4 ± 0.035^a
Total	55 ± 0.75^gh	72.5 ± 0.38^c	75.1 ± 0.40^b	76.1 ± 0.39^ab	76.8 ± 0.40^a	23 ± 0.96^k	38.34 ± 0.30^j	39.1 ± 0.31^ij	40 ± 0.52ⁱ	40.9 ± 0.27ⁱ	49 ± 0.94^hi	67.61 ± 0.36^e	68.9 ± 0.39^de	70 ± 0.40^d	68.1 ± 0.40^e	37 ± 0.79^jk	54.8 ± 0.33^h	56.4 ± 0.36^g	57.6 ± 0.38^fg	58.2 ± 0.40^f
4-hba
Bound	0.4 ± 0.06^gh	0.37 ± 0.024^h	0.34 ± 0.024^hi	0.28 ± 0.023ⁱ	0.23 ± 0.023^j	0.7 ± 0.03^de	0.65 ± 0.023^de	0.61 ± .011^e	0.58 ± 0.018^ef	0.53 ± 0.017^f	1.3 ± 0.3^b	1.1 ± 0.045^c	0.8 ± 0.029^d	0.5 ± 0.017^g	1.3 ± 0.049^c	1.8 ± 0.04^c	1.6 ± 0.039^ab	1.2 ± 0.032^bc	0.9 ± 0.021^cd	0.5 ± 0.019^g
Free	N.D	0.8 ± 0.04^g	1.3 ± 0.06^ef	1.6 ± 0.03^e	1.1 ± 0.02^fg	N.D	1.2 ± 0.03^f	1.6 ± 0.04^e	2.2 ± 0.06^d	2.5 ± 0.04^c	N.D	2.1 ± 0.03^de	2.5 ± 0.04^c	3.1 ± 0.06^b	2.4 ± 0.03^cd	N.D	2.5 ± 0.04^c	2.9 ± 0.03^bc	3.3 ± 0.07^ab	3.8 ± 0.06^a
Total	0.4 ± 0.06^j	1.17 ± 0.05^hi	1.64 ± 0.07^g	1.88 ± 0.04^f	1.33 ± 0.03^gh	0.7 ± 0.03ⁱ	1.85 ± 0.05^fg	2.21 ± 0.06^ef	2.78 ± 0.07^e	3.03 ± 0.05^de	1.3 ± 0.3^h	3.2 ± 0.07^de	3.3 ± 0.06^cd	3.6 ± 0.07^bc	3.7 ± 0.07^bc	1.8 ± 0.04^fg	4.1 ± 0.07^b	4.1 ± 0.06^b	4.2 ± 0.09^ab	4.3 ± 0.07^a
Van
Free	1.1 ± 0.10^k	3.8 ± 0.12^j	4.2 ± 0.15^hj	4.5 ± 0.16^h	4.8 ± 0.17^gh	16 ± 0.60^d	17.2 ± 0.25^c	17.5 ± 0.26^b	18.1 ± 0.24^b	18.6 ± 0.26^a	10 ± 0.70^g	12.7 ± 0.25^f	13.8 ± 0.26^ef	14.3 ± 0.21^e	13.5 ± 0.29^ef	15 ± 0.84^de	16.3 ± 0.27^cd	17.6 ± 0.23^bc	18.1 ± 0.28^b	18.4 ± 0.27^ab
Bound	N.D	0.09 ± 0.011^g	0.14 ± 0.015^ef	0.17 ± 0.013^d	0.19 ± 0.012^cd	N.D	0.21 ± 0.023^c	0.23 ± 0.024^bc	0.25 ± 0.023^ab	0.28 ± 0.026^a	N.D	0.11 ± 0.011^f	0.15 ± 0.015^e	0.17 ± 0.013^d	0.11 ± 0.011^f	N.D	0.16 ± 0.014^de	0.19 ± 0.016^cd	0.21 ± 0.018^c	0.14 ± 0.019^b
Total	1.1 ± 0.1^j	3.92 ± 0.13^ij	4.35 ± 0.16ⁱ	4.66 ± 0.17hi	4.97 ± 0.18^h	16 ± 0.6^de	17.4 ± 0.17^cd	17.7 ± 0.28^c	18.3 ± 0.26^ab	18.8 ± 0.28^ab	10 ± 0.7	12.9 ± 0.26	14.0 ± 0.27	14.5 ± 0.22	13.7 ± 0.30	15 ± 0.84	16.5 ± 0.28	17.8 ± 0.24	18.3 ± 0.29	18.6 ± 0.28

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Fer; ferulic acid, t-fer; trans-ferulic acid, Gal; gallic acid, p-Cou; p-Coumaric acid, 4-hba; 4-hydroxy benzoic acid, Van; vanillic acid. The results are expressed as mean ± standard deviation (n = 3). All phenolic are expressed in mg/kg; N.D., not detected; Means with similar letters in a column for non-basmati and basmati varieties do not differ significantly. The grouping is done in row by the application of Tukey’s test (p < 0.05) where the superscript “a” indicates the highest value among the group. The results are expressed as mean ± standard deviation (n = 3)

Amino acid composition

A total of seventeen amino acids were identified in both control-germinated and ultrasound-germinated BR from all varieties (Table 6). The study demonstrated that ultrasound treatment led to a significant increase in TEAA and GABA levels during germination. Both variety and ultrasonication had a notable impact on the EAA content across different varieties indicated by statistical analysis ANOVA. The F values suggested that ultrasonication had a greater effect on GABA than on the other amino acids, whereas the influence of the varieties is more pronounced than that of ultrasonication for other amino acids (Table S5). Among the non-essential amino acids (NEAAs), glutamic acid exhibited the highest concentration, ranging from 11.3 to 12.52 mg/g, followed by aspartic acid, which ranged from 6.94 to 7.91 mg/g, and arginine, which ranged from 4.24 to 6.05 mg/g. On the other hand, tyrosine and alanine contributed the least to the amount of NEAAs in the BR across all varieties, with concentrations ranging from 2.07 to 2.94 mg/g and 3.22 to 3.65 mg/g, respectively. The glutamic acid and aspartic acid contents decreased in the control-germinated BR compared to those in the BR, with glutamic acid ranging from 9.2 to 11 mg/g and aspartic acid ranging from 3.6 to 5.2 mg/g. The ultrasonicated-germinated BR showed the greatest reduction in glutamic acid (34%) for the PR121 US 10 min and in aspartic acid (63%) for the PB1121 US 15 min. Generally, amino acids are produced through proteolysis or amino acid metabolism during germination, which can increase the overall concentrations of free amino acids (Ding et al. 2018a). The contents of aspartic acid, glutamic acid, serine, glycine, alanine, and histidine and isoleucine, leucine, methionine, lysine, valine, phenylalanine, and threonine decreased in the control-germinated and ultrasonicated-germinated BR from all varieties, which was reflected in the increase in TEAA. Among the ultrasonicated-germinated BR, the highest increased in the TEAA of 65% was observed for the PR129 US 10 min, and the lowest increase of 38% was observed for the PR124 US 10 min. An increase in amino acid metabolism changed the level of certain amino acids during germination. For example, the aspartic acid and glutamic acid pathway could led to the synthesis of the EAA such as lysine, threonine, methionine, isoleucine and GABA, respectively, by consuming aspartate and glutamic acid (Galili and Höfgen 2002; Ding et al. 2018a). Furthermore, ultrasound waves attributed to the breakdown of cell walls during ultrasonication enhanced water absorption and increased the germination rate, resulting in an increase in essential amino acids and a decrease in aspartic acid and glutamic acid in the control germinated sample (Xia et al. 2020; Banura and Singh 2023). Among the different ultrasonication times, the PR113, PR121, PR124, PR129, and CSR30 varieties showed the greatest increase in TEAA and GABA for 10 min of ultrasonication, while the PB1121, PB1509, and PB1637 varieties showed for 15 min of ultrasonication treatment. The greatest increase in lysine (63%) and isoleucine (58%) content was detected for PB1637 US 15 min, whereas the greatest increase in methionine (39%) and phenylalanine (49%) content was detected for PB1121 US for 15 min. Compared with that in the control-germinated BR, the GABA content continuously increased as the ultrasonication time increased. Based on studies, it appears that ultrasound treatment may promote the synthesis of GABA and EAAs throughout the germination process. The maximum and minimum changes in GABA were observed for PB1637 US for 15 min (108%) and PR124 US for 10 min (79%), respectively. Ding et al. (2018a) showed a comparable rise in GABA content. The GABA producing mechanism consists of glutamate, glutamate decarboxylase (GAD), and GABA transaminase. GAD activity in the BR boosts throughout germination process, and GABA is regularly generated (Oh et al. 2003). Similarly, ultrasonic method during soaking and germination may boost GABA levels by activating GAD activity in seeds. Oh et al. (2003) found that BR germination boosted GAD activity while decreasing glutamate concentration. It appears likely that GAD activity increased as germination progressed, and hence GABA was continuously produced. Hence, ultrasonic wave treatment can cause stress on seeds, which might enhance the metabolism and germination activity of rice grain, leading to enhanced accumulation of GABA by enhancing GAD activity. Similarly, Zhang et al. (2016) observed that the GABA in ultrasonicated-germinated BR at multiple frequencies and treatment times (5–30 min) steadily improved with treatment time till 15 min, beyond it dropped. Our findings suggest that germinated BR treated with ultrasound can be used as an excellent source of GABA-rich foods.

Table 6.

Amino acid composition of BR, germinated control BR, ultrasonicated (5, 10 and 15 min) germinated BR from various non-basmati and basmati varieties

Non-basmati
	PR113					PR121					PR124					PR129
	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min
Iso	2.41 ± 0.05^hi	2.87 ± 0.06^fg	3.43 ± 0.05^c	3.64 ± 0.05^ab	3.16 ± 0.04^de	2.48 ± 0.09^gh	2.90 ± 0.07^g	3.07 ± 0.06^f	3.50 ± 0.04^b	3.20 ± 0.05^cd	2.46 ± 0.06^h	2.87 ± 0.06^gh	3.15 ± 0.05^e	3.48 ± 0.04^bc	3.12 ± 0.05^ef	2.54 ± 0.08^g	2.97 ± 0.07^g	3.17 ± 0.05^d	3.71 ± 0.05^a	3.06 ± 0.06^fg
leu	6.21 ± 0.04^j	7.49 ± 0.08^h	9.08 ± 0.06^bc	9.30 ± 0.06^b	7.99 ± 0.05^j	6.38 ± 0.05^ij	7.67 ± 0.04^g	8.77 ± 0.05^de	10.3 ± 0.05^ab	8.79 ± 0.06^d	5.99 ± 0.05^k	7.27 ± 0.07^hi	7.73 ± 0.06^fg	8.86 ± 0.07^cd	7.59 ± 0.08^gh	7.14 ± 0.07ⁱ	8.55 ± 0.09^ef	8.95 ± 0.07^c	12.40 ± 0.14^a	8.65 ± 0.09^e
Met	1.03 ± 0.06^jk	1.14 ± 0.05^j	1.24 ± 0.04ⁱ	1.43 ± 0.04^f	1.15 ± 0.03^ij	1.55 ± 0.03^de	1.64 ± 0.03^cd	1.78 ± 0.04^b	1.90 ± 0.05^ab	1.71 ± 0.03^bc	1.43 ± 0.08^fg	1.54 ± 0.05^e	1.54 ± 0.04^d	1.95 ± 0.06^a	1.51 ± 0.04^ef	1.25 ± 0.09^hi	1.34 ± 0.06^gh	1.37 ± 0.04^g	1.66 ± 0.05^c	1.27 ± 0.05^h
Lys	2.38 ± 0.08^k	3.06 ± 0.09^hi	3.50 ± 0.07^d	3.66 ± 0.05^bc	3.12 ± 0.05^gh	2.58 ± 0.05ⁱ	3.34 ± 0.05^e	3.52 ± 0.05^c	4.12 ± 0.06^ab	3.51 ± 0.05^cd	2.51 ± 0.09^j	3.15 ± 0.04^g	3.34 ± 0.03^de	4.13 ± 0.09^a	3.09 ± 0.05^h	2.55 ± 0.08^ij	3.22 ± 0.04^fg	3.33 ± 0.06^ef	3.85 ± 0.09^b	3.28 ± 0.06^f
Val	5.08 ± 0.08ⁱ	6.26 ± 0.08^d	7.30 ± 0.06^b	7.43 ± 0.07^ab	6.58 ± 0.03^c	4.19 ± 0.08^j	5.20 ± 0.06^h	5.62 ± 0.04^f	6.19 ± 0.05^de	5.48 ± 0.07^fg	4.92 ± 0.07^ij	6.07 ± 0.05^e	6.38 ± 0.06^cd	7.05 ± 0.08^bc	5.72 ± 0.06^ef	4.15 ± 0.06^k	5.15 ± 0.07^hi	5.41 ± 0.07^g	8.04 ± 0.1^a	5.28 ± 0.04^gh
His	1.62 ± 0.09^a	1.52 ± 0.06^ab	1.24 ± 0.05^ef	1.18 ± 0.05^hi	1.46 ± 0.05^b	1.46 ± 0.06^bc	1.33 ± 0.04^d	1.2 ± 0.03^gh	1.24 ± 0.04^f	1.30 ± 0.03^de	1.39 ± 0.08^c	1.24 ± 0.07^fg	1.23 ± 0.02^g	0.99 ± 0.03^ij	1.29 ± 0.03^e	1.35 ± 0.05^cd	1.29 ± 0.034^g	1.16 ± 0.03ⁱ	0.88 ± 0.02^j	1.20 ± 0.05^h
Thr	1.79 ± 0.02^k	1.83 ± 0.03^j	1.89 ± 0.04ⁱ	1.92 ± 0.06^hi	1.855 ± 0.05^ij	2.03 ± 0.03^fg	2.12 ± 0.06^d	2.23 ± 0.05^b	2.29 ± 0.05^ab	2.17 ± 0.05^bc	1.95 ± 0.04^h	2.04 ± 0.03^f	2.00 ± 0.04^g	2.11 ± 0.06^de	1.95 ± 0.05^gh	2.07 ± 0.01^ef	2.06 ± 0.05^c	2.13 ± 0.06^cd	2.30 ± 0.04^a	2.10 ± 0.06^e
Phe	2.03 ± 0.02^k	2.03 ± 0.04^jk	2.77 ± 0.05ⁱ	2.89 ± 0.03^fg	2.56 ± 0.03^ij	2.84 ± 0.05^gh	3.24 ± 0.03^d	3.50 ± 0.06^bc	4.00 ± 0.08^a	3.60 ± 0.06^b	2.78 ± 0.05^hi	3.12 ± 0.06^e	3.45 ± 0.03^cd	3.82 ± 0.04^ab	3.02 ± 0.04^ef	2.47 ± 0.03^j	3.21 ± 0.06^g	3.18 ± 0.07^de	3.49 ± 0.06^c	2.95 ± 0.04^f
Tyr	2.11 ± 0.04^ij	2.30 ± 0.05^h	2.58 ± 0.06^fg	2.68 ± 0.05^f	2.26 ± 0.05ⁱ	2.07 ± 0.03^j	2.29 ± 0.04^hi	2.69 ± 0.03^ef	2.85 ± 0.03^cd	2.41 ± 0.04^gh	2.55 ± 0.04^g	2.79 ± 0.06^d	2.94 ± 0.02^b	3.46 ± 0.03^ab	2.75 ± 0.02^e	2.52 ± 0.04^g	2.25 ± 0.03^de	2.91 ± 0.03^bc	3.78 ± 0.05^a	2.86 ± 0.05^c
Pro	3.45 ± 0.06^j	4.22 ± 0.03^f	5.19 ± 0.04^bc	5.33 ± 0.05^b	4.70 ± 0.03^cd	3.57 ± 0.06^ij	4.14 ± 0.06^g	4.85 ± 0.056^c	5.39 ± 0.05^ab	4.55 ± 0.05^de	3.29 ± 0.07^jk	3.79 ± 0.08^h	4.04 ± 0.04^gh	4.66 ± 0.04^d	3.70 ± 0.05^hi	3.62 ± 0.05ⁱ	4.20 ± 0.06^fg	4.53 ± 0.06^e	5.94 ± 0.07^a	4.24 ± 0.03^ef
Arg	4.99 ± 0.05^j	5.96 ± 0.05^h	7.03 ± 0.06^cd	7.35 ± 0.06^c	6.77 ± 0.05^e	6.02 ± 0.07^gh	6.84 ± 0.056^de	7.66 ± 0.06^bc	8.26 ± 0.07^a	7.76 ± 0.06^b	6.05 ± 0.08^g	6.91 ± 0.09^d	7.76 ± 0.05^b	8.26 ± 0.1^a	6.73 ± 0.07^ef	5.16 ± 0.08ⁱ	6.79 ± 0.04^hi	6.66 ± 0.08^f	8.21 ± 0.09^ab	6.15 ± 0.06^fg
Asp acid	6.94 ± 0.08^b	3.79 ± 0.06^fg	3.30 ± 005^ij	2.85 ± 0.04^j	3.45 ± 0.03^gh	6.72 ± 0.08^bc	3.67 ± 0.086^g	3.41 ± 0.03^h	2.82 ± 0.05^jk	3.37 ± 0.05^hi	7.15 ± 0.09^ab	4.16 ± 0.07^ef	3.88 ± 0.02^f	3.30 ± 0.03ⁱ	4.32 ± 0.05^de	7.82 ± 0.12^a	5.18 ± 0.06^c	4.82 ± 0.05^d	4.23 ± 0.06^e	5.05 ± 0.07^cd
Glut acid	11.76 ± 0.15^bc	10.01 ± 0.16^gh	9.37 ± 0.14^ij	9.97 ± 0.13^h	9.73 ± 0.16^hi	12.4 ± 0.11^ab	11.0 ± 0.156^cd	10.0 ± 0.12^gh	8.10 ± 0.15^j	10.3 ± 0.13^f	12.36 ± 0.13^b	10.95 ± 0.15^de	10.21 ± 0.14^fg	7.94 ± 0.09^k	9.71 ± 0.13ⁱ	12.52 ± 0.12^a	10.97 ± 0.14^d	10.5 ± 0.16^e	10.1 ± 0.14^g	10.4 ± 0.13^ef
Ser	3.84 ± 0.02^ab	3.68 ± 0.03^g	3.74 ± 0.06^e	3.77 ± 0.05^cd	3.70 ± 0.07^fg	3.79 ± 0.04^bc	3.70 ± 0.026^fg	3.73 ± 0.04^ef	3.74 ± 0.05^e	3.72 ± 0.04^f	3.86 ± 0.03^a	3.75 ± 0.04^de	3.82 ± 0.04^c	3.81 ± 0.03^b	3.76 ± 0.06^d	3.41 ± 0.04^gh	3.65 ± 0.05^ij	3.43 ± 0.05^hi	3.45 ± 0.05^h	3.42 ± 0.04ⁱ
Gly	3.42 ± 0.05^ab	3.24 ± 0.04^cd	2.54 ± 0.03^hi	2.49 ± 0.03ⁱ	3.08 ± 0.04^e	3.29 ± 0.02^c	3.11 ± 0.056^de	2.79 ± 0.03^g	2.32 ± 0.03^ij	2.90 ± 0.05^fg	3.57 ± 0.04^a	3.41 ± 0.02^b	2.23 ± 0.05^d	2.95 ± 0.03^f	3.36 ± 0.05^bc	3.07 ± 0.05^ef	2.90 ± 0.06^fg	2.67 ± 0.04^h	2.02 ± 0.04^j	2.71 ± 0.05^gh
Ala	3.22 ± 0.04^bc	2.67 ± 0.05^h	2.19 ± 0.04^j	2.08 ± 0.06^k	2.47 ± 0.05^ij	3.58 ± 0.04^a	3.08 ± 0.046^d	2.90 ± 0.05^e	2.65 ± 0.05^hi	2.80 ± 0.04^f	3.44 ± 0.05^b	3.09 ± 0.03^cd	2.76 ± 0.03^fg	2.62 ± 0.05ⁱ	2.70 ± 0.07^g	3.56 ± 0.03^ab	3.13 ± 0.04^c	2.86 ± 0.06^ef	2.69 ± 0.05^gh	3.08 ± 0.06^de
GABA	1.93 ± 0.01^ij	3.25 ± 0.03^e	3.46 ± 0.05^c	3.61 ± 0.04^bc	3.31 ± 0.03^de	1.48 ± 0.04^j	2.28 ± 0.016^h	2.40 ± 0.03^gh	2.71 ± 0.04^fg	2.49 ± 0.05^g	2.05 ± 0.02ⁱ	3.11 ± 0.04^ef	3.65 ± 0.05^cd	3.67 ± 0.06^ab	3.08 ± 0.06^f	2.16 ± 0.04^hi	3.31 ± 0.06^de	3.63 ± 0.04^b	3.89 ± 0.06^a	3.35 ± 0.05^d
TNAA	39.73 ± 0.49^c	35.96 ± 0.47^j	35.97 ± 0.48^ij	36.55 ± 0.47^h	36.21 ± 0.48^hi	41.41 ± 0.45^b	37.9 ± 0.496^f	38.0 ± 0.41^ef	36.1 ± 0.48ⁱ	37.8 ± 0.47^fg	42.27 ± 0.53^a	38.88 ± 0.54^cd	37.0 ± 0.39^d	37.04 ± 0.4^gh	37.0 ± 0.5^g	41.78 ± 0.53^ab	38.54 ± 0.48^de	38.4 ± 0.53^e	40.4 ± 0.55^bc	38.0 ± 0.49^ef
TEAA	22.61 ± 0.44^j	26.44 ± 0.49^hi	30.53 ± 0.42^c	31.48 ± 0.41^bc	27.92 ± 0.33^ef	23.51 ± 0.44ⁱ	27.4 ± 0.446^g	29.7 ± 0.38^d	33.6 ± 1.14^ab	29.8 ± 0.4^cd	23.43 ± 0.52^ij	27.34 ± 0.43^h	28.87 ± 0.33^de	32.48 ± 0.47^b	27.3 ± 0.4^gh	23.52 ± 0.47ⁱ	27.0 ± 0.47^fg	28.7 ± 0.45^e	36.3 ± 0.55^a	27.8 ± 0.45^f

Basmati
	PR1121					PB1509					CSR30					PB1637
	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min	BR	Germ. cont.	US 5 min	US 10 min	US 15 min
Iso	2.53 ± 0.06^h	3.06 ± 0.05^f	3.17 ± 0.06^ef	3.67 ± 0.05^cd	3.87 ± 0.06^ab	2.56 ± 0.05^gh	3.03 ± 0.05^f	3.33 ± 0.06^d	3.76 ± 0.05^c	3.92 ± 0.04^a	2.49 ± 0.06^hi	2.95 ± 0.05^g	3.17 ± 0.04^ef	3.83 ± 0.05^b	3.19 ± 0.04^e	2.47 ± 0.06ⁱ	2.97 ± 0.05^fg	3.27 ± 0.05^de	3.78 ± 0.06^bc	3.92 ± 0.07^a
leu	5.49 ± 0.06^k	6.65 ± 0.06ⁱ	6.96 ± 0.11^hi	7.77 ± 0.12^ef	8.16 ± 0.04^de	6.41 ± 0.07^ij	7.58 ± 0.09^fg	8.13 ± 0.09^e	8.94 ± 0.1^cd	9.41 ± 0.04^bc	5.81 ± 0.05^j	7.02 ± 0.09^h	7.31 ± 0.09^gh	8.78 ± 0.09^d	7.51 ± 0.09^g	7.61 ± 0.06^f	9.25 ± 0.09^c	9.78 ± 0.11^b	11.4 ± 0.13^ab	11.85 ± 0.12^a
Met	1.66 ± 0.08^fg	1.78 ± 0.04^ef	1.85 ± 0.05^de	2.19 ± 0.04^b	2.30 ± 0.06^a	1.63 ± 0.08^g	1.76 ± 0.04^f	1.81 ± 0.04^e	2.11 ± 0.04^bc	2.25 ± 0.04^ab	1.52 ± 0.08^hi	1.63 ± 0.05^g	1.66 ± 0.04^fg	2.05 ± 0.06^c	1.47 ± 0.05^cd	1.45 ± 0.08ⁱ	1.54 ± 0.06^h	1.57 ± 0.04^gh	1.85 ± 0.05^de	1.96 ± 0.04^d
Lys	2.96 ± 0.07ⁱ	3.84 ± 0.06^ef	3.97 ± 0.06^d	4.59 ± 0.05^b	4.71 ± 0.04^a	2.63 ± 0.06^jk	3.30 ± 0.05^hi	3.50 ± 0.05^gh	3.50 ± 0.06^de	4.09 ± 0.04^cd	2.85 ± 0.07^ij	3.65 ± 0.06^f	3.91 ± 0.05^e	4.64 ± 0.05^ab	3.57 ± 0.06^g	2.68 ± 0.08^j	3.44 ± 0.07^h	3.61 ± 0.05^fg	4.36 ± 0.05^c	4.39 ± 0.06^bc
Val	5.14 ± 0.11^ij	6.57 ± 0.07^fg	6.84 ± 0.08^ef	7.57 ± 0.1^cd	7.95 ± 0.06^b	5.17 ± 0.06^ij	6.28 ± 0.07^h	6.53 ± 0.03^g	7.32 ± 0.04^de	7.66 ± 0.04^bc	5.01 ± 0.09^j	6.34 ± 0.07^gh	6.72 ± 0.08^f	7.58 ± 0.07^c	6.08 ± 0.07^hi	5.47 ± 0.09ⁱ	6.97 ± 0.06^e	7.36 ± 0.06^d	8.10 ± 0.06^ab	8.28 ± 0.08^a
His	1.74 ± 0.07^bc	1.77 ± 0.04^b	1.59 ± 0.03^de	1.37 ± 0.05^g	1.29 ± 0.03^hi	1.63 ± 0.06^cd	1.60 ± 0.05^d	1.47 ± 0.05^ef	1.32 ± 0.06^h	1.27 ± 0.04ⁱ	1.46 ± 0.07^f	1.49 ± 0.04^e	1.29 ± 0.04^hi	1.07 ± 0.02^j	1.41 ± 0.02^fg	1.83 ± 0.07^ab	1.84 ± 0.04^a	1.68 ± 0.03^c	1.47 ± 0.03^ef	1.36 ± 0.04^gh
Thr	1.86 ± 0.03^g	1.88 ± 0.06^fg	1.91 ± 0.05^f	1.95 ± 0.03^de	2.05 ± 0.05^b	1.69 ± 0.04ⁱ	1.75 ± 0.04^h	1.74 ± 0.03^hi	1.80 ± 0.04^gh	1.86 ± 0.04^g	1.95 ± 0.07^e	2.01 ± 0.05^c	2.00 ± 0.03^cd	2.10 ± 0.05^ab	1.96 ± 0.04^d	1.93 ± 0.05^ef	1.96 ± 0.06^d	2.00 ± 0.05^cd	2.05 ± 0.05^bc	2.14 ± 0.05^a
Phe	3.92 ± 0.02^hi	4.65 ± 0.05^f	5.24 ± 0.08^d	5.73 ± 0.07^ab	5.86 ± 0.06^a	3.88 ± 0.05ⁱ	4.33 ± 0.06^g	4.93 ± 0.05^ef	5.35 ± 0.06^cd	5.70 ± 0.04^b	3.57 ± 0.04^j	4.13 ± 0.06^h	4.62 ± 0.05^fg	5.01 ± 0.06^e	4.26 ± 0.06^gh	3.9 ± 0.03^hi	4.62 ± 0.06^fg	5.07 ± 0.06^de	5.44 ± 0.06^c	5.68 ± 0.04^bc
Tyr	2.83 ± 0.05^h	3.02 ± 0.06^fg	3.03 ± 0.06^fg	3.60 ± 0.06^c	3.85 ± 0.03^ab	2.94 ± 0.04^g	3.18 ± 0.04^e	3.20 ± 0.06^de	3.64 ± 0.07^bc	3.90 ± 0.04^a	2.85 ± 0.04^gh	3.07 ± 0.04^f	3.08 ± 0.05^ef	3.74 ± 0.04^b	2.93 ± 0.04^g	2.71 ± 0.03^ij	2.75 ± 0.04ⁱ	2.81 ± 0.03^hi	3.28 ± 0.06^d	3.42 ± 0.03^cd
Pro	3.27 ± 0.07^j	4.02 ± 0.08^gh	4.39 ± 3.06^f	4.91 ± 0.06^d	5.09 ± 0.06^c	3.32 ± 0.08^ij	3.99 ± 0.06^h	4.41 ± 0.07^ef	4.95 ± 0.05^cd	5.22 ± 0.04^b	3.41 ± 0.07ⁱ	4.25 ± 0.06^fg	4.63 ± 0.04^de	5.28 ± 0.05^a	4.41 ± 0.06^ef	3.49 ± 0.08^hi	4.19 ± 0.06^g	4.51 ± 0.05^e	5.13 ± 0.04^bc	5.26 ± 0.03^ab
Arg	4.31 ± 0.05ⁱ	5.17 ± 0.06^g	5.91 ± 9.06^e	6.31 ± 0.07^c	6.43 ± 0.07^bc	4.47 ± 0.05^hi	5.29 ± 0.07^fg	5.95 ± 0.05^de	6.28 ± 0.07^cd	6.69 ± 0.04^ab	4.24 ± 0.06^ij	5.15 ± 0.06^gh	5.77 ± 0.06^ef	6.18 ± 0.06^d	5.28 ± 0.07^fg	4.58 ± 0.04^h	5.58 ± 0.04^f	6.28 ± 0.07^cd	6.60 ± 0.06^b	6.80 ± 0.05^a
Asp	7.91 ± 0.13^a	4.15 ± 0.07^d	3.65 ± 8.06^f	3.34 ± 0.05^h	2.91 ± 0.05^jk	7.58 ± 0.13^b	4.29 ± 0.05^c	3.87 ± 0.06^e	3.55 ± 0.05^g	2.93 ± 0.04^j	7.26 ± 0.13^bc	3.82 ± 0.05^ef	3.62 ± 0.07^fg	3.26 ± 0.04^hi	2.95 ± 0.04^ij	7.65 ± 0.14^ab	4.20 ± 0.05^cd	3.88 ± 0.05^de	3.38 ± 0.04^gh	3.02 ± 0.05ⁱ
Glut	11.36 ± 0.13^b	9.28 ± 0.14^g	9.15 ± 0.13^h	9.00 ± 0.17^ij	8.83 ± 0.11^jk	11.32 ± 0.12^bc	9.60 ± 0.11^de	9.48 ± 0.11^f	9.20 ± 0.13^gh	8.94 ± 0.04^j	11.55 ± 0.12^ab	9.55 ± 0.11^e	9.54 ± 0.13^ef	9.33 ± 0.11^fg	9.05 ± 0.13ⁱ	12.09 ± 0.14^a	9.99 ± 0.12^c	9.72 ± 0.13^cd	9.70 ± 0.15^d	9.12 ± 0.13^hi
Ser	4.68 ± 0.05^ab	4.48 ± 0.05^e	4.50 ± 0.04^de	4.55 ± 0.06^d	4.57 ± 0.04^cd	4.73 ± 0.05^a	4.57 ± 0.05^cd	4.61 ± 0.04^c	4.64 ± 0.05^hi	4.66 ± 0.04^b	3.55 ± 0.02^hi	3.38 ± 0.04^jk	3.43 ± 0.05^j	3.46 ± 0.04ⁱ	3.44 ± 0.05^ij	4.05 ± 0.04^fg	3.90 ± 0.05^gh	3.94 ± 0.05^g	4.12 ± 0.05^ef	4.09 ± 0.04^f
Gly	3.81 ± 0.02^a	3.50 ± 0.0^b	3.29 ± 0.05^d	2.76 ± 0.04^gh	2.61 ± 0.03^hi	3.55 ± 0.04^ab	3.42 ± 0.06^c	3.17 ± 0.05^f	2.64 ± 0.03^h	2.50 ± 0.04^ij	3.39 ± 0.05^cd	3.24 ± 0.05^de	2.98 ± 0.06^g	2.53 ± 0.03ⁱ	3.18 ± 0.04^ef	3.48 ± 0.02^bc	3.21 ± 0.03^e	3.00 ± 0.06^fg	2.48 ± 0.03^j	2.22 ± 0.05^jk
Ala	3.65 ± 0.04^a	3.01 ± 0.04^cd	2.76 ± 0.06^f	2.59 ± 0.05^h	2.38 ± 0.05^ij	3.64 ± 0.04^ab	3.08 ± 0.05^c	2.81 ± 0.03^e	2.60 ± 0.05^gh	2.38 ± 0.04^ij	3.58 ± 0.03^bc	2.91 ± 0.06^de	2.63 ± 0.03^g	2.45 ± 0.05ⁱ	2.80 ± 0.05^ef	3.59 ± 0.03^b	2.93 ± 0.05^d	2.68 ± 0.03^fg	2.53 ± 0.05^hi	2.35 ± 0.03^j
GABA	2.75 ± 0.01^hi	4.81 ± 0.07^cd	5.21 ± 0.04^b	5.45 ± 0.07^ab	5.67 ± 0.06^a	2.41 ± 0.02ⁱ	4.00 ± 0.07^g	4.37 ± 0.03^ef	4.66 ± 0.05^de	4.90 ± 0.04^c	2.24 ± 0.03^j	3.89 ± 0.03^h	4.21 ± 0.05^f	4.44 ± 0.06^e	3.92 ± 0.03^gh	2.36 ± 0.02^ij	4.10 ± 0.03^fg	4.44 ± 0.06^e	4.71 ± 0.06^d	4.93 ± 0.05^bc
TNAA	41.82 ± 0.54^a	36.6 ± 0.56^g	36.7 ± 0.48^f	37.1 ± 0.56^de	36.7 ± 0.44^fg	41.55 ± 0.55^b	37.4 ± 0.49^cd	37.5 ± 0.47^c	37.53 ± 0.5^c	37.2 ± 0.04^d	39.83 ± 0.52^bv	35.4 ± 0.47ⁱ	35.7 ± 0.49^hi	36.2 ± 0.42^h	34.08 ± 0.48^ij	41.64 ± 0.52^ab	36.7 ± 0.44^ef	36.8 ± 0.47^e	37.2 ± 0.48^d	36.32 ± 0.44^gh
TEAA	25.3 ± 0.5^ij	30.2 ± 0.43^fg	31.5 ± 0.52^e	34.8 ± 0.51^c	36.2 ± 0.40^b	25.6 ± 0.47ⁱ	29.6 ± 0.45^gh	31.4 ± 0.4^ef	34.56 ± 0.45^cd	36.2 ± 0.04^b	24.66 ± 0.53^j	29.2 ± 0.47^h	30.7 ± 0.42^f	35.0 ± 0.45^bc	30.0 ± 0.43^g	27.34 ± 0.52^hi	32.6 ± 0.49^de	34.3 ± 0.45^d	38.5 ± 0.49^ab	39.60 ± 0.99^a

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A.A.; Amino acid are expressed in mg/g; (TNAA, total non-essential amino acid; Pro, proline; Asp, aspartic acid; Glut, glutamic acid; Arg, arginine; Ser, serine; Tyr, tyrosine; GABA-γ-aminobutric acid and Ala, Alanin) TEAA, total essential amino acid; Iso; isoleucine; leu; leucine; Val, valine; Met, methionine; Phe, phenylalanine; Trp- Tryptophan; His, histidine; Lys, lysine; Thr, threonine; (TAAA; total aromatic amino acid, Phe, phenylalanine; Tyr, tyrosine). The results are expressed as mean ± standard deviation (n = 3). Means with similar letters in a column for basmati and non-basmati varieties do not differ significantly. The grouping is done in row by the application of Tukey’s test (p < 0.05) where the superscript “a” indicates the highest value among the group

Conclusion

This study elucidated the effects of ultrasonication treatment time (5, 10 and 15 min) during the soaking step of germination on the overall quality of germinated BR. GABA, TDF, phenolic profile and EAAs improved prominently in BR in ultrasonicated germinated BR. The most notable effect was observed in 10 min of ultrasonication treatment for the PR121, PR113, PR124, PR129, and CSR30 varieties and 15 min of ultrasonication treatment for the PB1121, PB1509, and PB1637 varieties resulted in the highest germination capacity on the basis of alpha-amylase activity, starch degradation, reduction in phytic acid content, and accumulation of GABA and TEAA. Compared with that in the control-germinated BR, the GABA content continuously increased as the ultrasonication time increased. The highest GABA content was observed for PB1121 US 15 min. Ultrasound has emerged as a key method for developing of germinated grain ingredients, providing major benefits to breeding researchers and grain seedling propagators. Its application assists in accelerating the seedling growth cycle, increasing sprouting efficiency, and lowering production costs.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 85 kb)^{(85.5KB, docx)}

Acknowledgements

SM acknowledges PMR fellowship for financial support sponsoring by Mr. Vijay Setia, Chaman Lal Setia Exports ltd. NS acknowledges financial support from Ministry of Food Processing Industry and JC Bose National Fellowship by SERB. Authors acknowledges the DST-FIST financial support. We are also thankful to Director Dr. Paramjeet Singh and Dr. Onkar Singh for providing rice samples from Rice Regional Centre, PAU, Kapurthala.

Author contributions

Swasti Mudgal: Formal analysis, Methodology, Data curation, Investigation, Writing—original draft, Writing—review and editing. Narpinder Singh: Conceptualization, Supervision, Resources, Funding acquisition, Project administration, Formal analysis, Investigation, Writing—review and editing.

Funding

JC BOSE Fellowship, JBR/2020/000045, Narpinder Singh, MOFPI, Q-11/1/2019-R&D, Narpinder Singh, Science Education Research Board, SERB/PM Fellow/CII-FICCI/Meeting/2019, Swasti Mudgal

Availability of data and material

All the data is original presented in the manuscript and authors have content to publish in your journal.

Code availability

Not applicable.

Declarations

Conflict of interest

The authors declare that that they have no conflict of interest.

Ethical approval

Ethics approval was not required for this research.

Consent to participate

Authors have no conflict of interest to publish the given data.

Consent for publication

Authors have consent to publish data and image in the given manuscript.

Footnotes

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

American Association of Cereal Chemists. Approved Methods Committee (2000) Approved methods of the American association of cereal chemists (vol 1). American Association of Cereal Chemists
AOAC (1990) Official method of analysis 15th Edn. Association of Official Analytical Chemist. Washington, DC. USA
Banura S, Singh N (2023) Effect of ultrasonication on physicochemical, amino-acids, sugar profile, antioxidant, pasting, and dynamic rheological properties of malted mung beans and lentils. Int J Food Sci Technol 58(5):2476–2488 [Google Scholar]
Bhinder S, Kumari S, Singh B, Kaur A, Singh N (2021) Impact of germination on phenolic composition, antioxidant properties, antinutritional factors, mineral content and Maillard reaction products of malted quinoa flour. Food Chem 346:128915 [DOI] [PubMed] [Google Scholar]
Chen YP, Liu Q, Yue XZ, Meng ZW, Liang J (2013) Ultrasonic vibration seeds showed improved resistance to cadmium and lead in wheat seedling. Environ Sci Pollut Res 20:4807–4816 [DOI] [PubMed] [Google Scholar]
Cornejo F, Caceres PJ, Martínez-Villaluenga C, Rosell CM, Frias J (2015) Effects of germination on the nutritive value and bioactive compounds of brown rice breads. Food Chem 173:298–304 [DOI] [PubMed] [Google Scholar]
Ding J, Hou GG, Dong M, Xiong S, Zhao S, Feng H (2018a) Physicochemical properties of germinated dehulled rice flour and energy requirement in germination as affected by ultrasound treatment. Ultrason Sonochem 41:484–491 [DOI] [PubMed] [Google Scholar]
Ding J, Ulanov AV, Dong M, Yang T, Nemzer BV, Xiong S, Zhao S, Feng H (2018b) Enhancement of gama-aminobutyric acid (GABA) and other health-related metabolites in germinated red rice (Oryza sativa L.) by ultrasonication. Ultrason Sonochem 40:791–797 [DOI] [PubMed] [Google Scholar]
Estivi L, Brandolini A, Condezo-Hoyos L, Hidalgo A (2022) Impact of low-frequency ultrasound technology on physical, chemical and technological properties of cereals and pseudocereals. Ultrason Sonochem 86:106044 [DOI] [PMC free article] [PubMed] [Google Scholar]
Galili G, Höfgen R (2002) Metabolic engineering of amino acids and storage proteins in plants. Metab Eng 4(1):3–11 [DOI] [PubMed] [Google Scholar]
Guzmán-Ortiz FA, Castro-Rosas J, Gómez-Aldapa CA, Mora-Escobedo R, Rojas-León A, Rodríguez-Marín ML, Falfán-Cortés RN, Román-Gutiérrez AD (2019) Enzyme activity during germination of different cereals: a review. Food Rev Intl 35(3):177–200 [Google Scholar]
He LY, Yang Y, Ren LK, Bian X, Liu XF, Chen FL, Zhang N (2022) Effects of germination time on the structural, physicochemical and functional properties of brown rice. Int J Food Sci Technol 57(4):1902–1910 [Google Scholar]
Jabeen R, Hussain SZ, Jan N, Fatima T, Naik HR, Jabeen A (2023) Comparative study of brown rice and germinated brown rice for nutritional composition, in vitro starch digestibility, bioactive compounds, antioxidant activity and microstructural properties. Cereal Chem 100(2):434–444 [Google Scholar]
Jiamyangyuen S, Ooraikul B (2008) The physico-chemical, eating and sensorial properties of germinated brown rice. J Food Agri Environ 6(2):119 [Google Scholar]
López-Ribera I, Vicient CM (2017) Use of ultrasonication to increase germination rates of Arabidopsis seeds. Plant Methods 13(1):1–6 [DOI] [PMC free article] [PubMed] [Google Scholar]
Majoral JP (ed) (2005) New Aspects in Phosphorus Chemistry V. Springer Science & Business Media, Berlin [Google Scholar]
Martín-Cabrejas MA, Díaz MF, Aguilera Y, Benítez V, Mollá E, Esteban RM (2008) Influence of germination on the soluble carbohydrates and dietary fibre fractions in non-conventional legumes. Food Chem 107(3):1045–1052 [Google Scholar]
Miano AC, Augusto PED (2018) The hydration of grains: a critical review from description of phenomena to process improvements. Compr Rev Food Sci Food Saf 17(2):352–370 [DOI] [PubMed] [Google Scholar]
Mohammadi F, Marti A, Nayebzadeh K, Hosseini SM, Tajdar-Oranj B, Jazaeri S (2021) Effect of washing, soaking and pH in combination with ultrasound on enzymatic rancidity, phytic acid, heavy metals and coliforms of rice bran. Food Chem 334:127583 [DOI] [PubMed] [Google Scholar]
Mudgal S, Singh N (2024). Effect of parboiling treatment times on the physicochemical, cooking, textural, and pasting properties and amino acid, phenolic, and sugar profiles of germinated paddy rice from different rice varieties. J Food Sci [DOI] [PubMed]
Mudgal S, Singh N (2022) Diversity in phenolics, amino acids, rheology and noodles glycemic response of brown rice from non-basmati and basmati rice. Food Res Int 158:111500 [DOI] [PubMed] [Google Scholar]
Oh SH, Soh JR, Cha YS (2003) Germinated brown rice extract shows a nutraceutical effect in the recovery of chronic alcohol-related symptoms. J Med Food 6(2):115–121 [DOI] [PubMed] [Google Scholar]
Oliveira MEAS, Coimbra PPS, Galdeano MC, Carvalho CWP, Takeiti CY (2022) How does germinated rice impact starch structure, products and nutritional evidences?—A review. Trends Food Sci Technol 122:13–23 [Google Scholar]
Pal P, Singh N, Kaur P, Kaur A, Virdi AS, Parmar N (2016) Comparison of composition, protein, pasting, and phenolic compounds of brown rice and germinated brown rice from different cultivars. Cereal Chem 93(6):584–592 [Google Scholar]
Prabhakar BN, Suneetha WJ, Devi SS, Shreeja K (2021) Effect of germination on nutritional composition of common buckwheat (Fagopyrum esculentum Moench). Int Res J Pure Appl Chem 22(1):1–7 [Google Scholar]
Sandhu RS, Singh N, Kaler RSS, Kaur A, Shevkani K (2018) Effect of degree of milling on physicochemical, structural, pasting and cooking properties of short and long grain Indica rice cultivars. Food Chem 260:231–238 [DOI] [PubMed] [Google Scholar]
Sibian MS, Saxena DC, Riar CS (2017) Effect of germination on chemical, functional and nutritional characteristics of wheat, brown rice and triticale: a comparative study. J Sci Food Agric 97(13):4643–4651 [DOI] [PubMed] [Google Scholar]
Singh N, Nakaura Y, Inouchi N, Nishinari K (2007) Fine structure, thermal and viscoelastic properties of starches separated from Indica rice cultivars. Starch-Stärke 59(1):10–20 [Google Scholar]
Su D, Sultan F, Zhao NC, Lei BT, Wang FB, Pan G, Cheng FM (2014) Positional variation in grain mineral nutrients within a rice panicle and its relation to phytic acid concentration. J Zhejiang Univer Sci B 15(11):986 [DOI] [PMC free article] [PubMed] [Google Scholar]
Xia Q, Tao H, Li Y, Pan D, Cao J, Liu L, Zhou X, Barba FJ (2020) Characterizing physicochemical, nutritional and quality attributes of wholegrain L. subjected to high intensity ultrasound-stimulated pre-germination. Food Control 108:106827 [Google Scholar]
Zhang Y, Zhao T, Shen J, Wang X (2016) Study on effect of ultrasonic treatment on GABA accumulation and antioxidant capacity in germinated brown rice. Sci Technol Food Ind 37(2):130–133 [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplementary file1 (DOCX 85 kb)^{(85.5KB, docx)}

Data Availability Statement

All the data is original presented in the manuscript and authors have content to publish in your journal.

Not applicable.

[CR1] American Association of Cereal Chemists. Approved Methods Committee (2000) Approved methods of the American association of cereal chemists (vol 1). American Association of Cereal Chemists

[CR2] AOAC (1990) Official method of analysis 15th Edn. Association of Official Analytical Chemist. Washington, DC. USA

[CR3] Banura S, Singh N (2023) Effect of ultrasonication on physicochemical, amino-acids, sugar profile, antioxidant, pasting, and dynamic rheological properties of malted mung beans and lentils. Int J Food Sci Technol 58(5):2476–2488 [Google Scholar]

[CR4] Bhinder S, Kumari S, Singh B, Kaur A, Singh N (2021) Impact of germination on phenolic composition, antioxidant properties, antinutritional factors, mineral content and Maillard reaction products of malted quinoa flour. Food Chem 346:128915 [DOI] [PubMed] [Google Scholar]

[CR5] Chen YP, Liu Q, Yue XZ, Meng ZW, Liang J (2013) Ultrasonic vibration seeds showed improved resistance to cadmium and lead in wheat seedling. Environ Sci Pollut Res 20:4807–4816 [DOI] [PubMed] [Google Scholar]

[CR6] Cornejo F, Caceres PJ, Martínez-Villaluenga C, Rosell CM, Frias J (2015) Effects of germination on the nutritive value and bioactive compounds of brown rice breads. Food Chem 173:298–304 [DOI] [PubMed] [Google Scholar]

[CR7] Ding J, Hou GG, Dong M, Xiong S, Zhao S, Feng H (2018a) Physicochemical properties of germinated dehulled rice flour and energy requirement in germination as affected by ultrasound treatment. Ultrason Sonochem 41:484–491 [DOI] [PubMed] [Google Scholar]

[CR8] Ding J, Ulanov AV, Dong M, Yang T, Nemzer BV, Xiong S, Zhao S, Feng H (2018b) Enhancement of gama-aminobutyric acid (GABA) and other health-related metabolites in germinated red rice (Oryza sativa L.) by ultrasonication. Ultrason Sonochem 40:791–797 [DOI] [PubMed] [Google Scholar]

[CR9] Estivi L, Brandolini A, Condezo-Hoyos L, Hidalgo A (2022) Impact of low-frequency ultrasound technology on physical, chemical and technological properties of cereals and pseudocereals. Ultrason Sonochem 86:106044 [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR10] Galili G, Höfgen R (2002) Metabolic engineering of amino acids and storage proteins in plants. Metab Eng 4(1):3–11 [DOI] [PubMed] [Google Scholar]

[CR11] Guzmán-Ortiz FA, Castro-Rosas J, Gómez-Aldapa CA, Mora-Escobedo R, Rojas-León A, Rodríguez-Marín ML, Falfán-Cortés RN, Román-Gutiérrez AD (2019) Enzyme activity during germination of different cereals: a review. Food Rev Intl 35(3):177–200 [Google Scholar]

[CR12] He LY, Yang Y, Ren LK, Bian X, Liu XF, Chen FL, Zhang N (2022) Effects of germination time on the structural, physicochemical and functional properties of brown rice. Int J Food Sci Technol 57(4):1902–1910 [Google Scholar]

[CR13] Jabeen R, Hussain SZ, Jan N, Fatima T, Naik HR, Jabeen A (2023) Comparative study of brown rice and germinated brown rice for nutritional composition, in vitro starch digestibility, bioactive compounds, antioxidant activity and microstructural properties. Cereal Chem 100(2):434–444 [Google Scholar]

[CR14] Jiamyangyuen S, Ooraikul B (2008) The physico-chemical, eating and sensorial properties of germinated brown rice. J Food Agri Environ 6(2):119 [Google Scholar]

[CR15] López-Ribera I, Vicient CM (2017) Use of ultrasonication to increase germination rates of Arabidopsis seeds. Plant Methods 13(1):1–6 [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR16] Majoral JP (ed) (2005) New Aspects in Phosphorus Chemistry V. Springer Science & Business Media, Berlin [Google Scholar]

[CR17] Martín-Cabrejas MA, Díaz MF, Aguilera Y, Benítez V, Mollá E, Esteban RM (2008) Influence of germination on the soluble carbohydrates and dietary fibre fractions in non-conventional legumes. Food Chem 107(3):1045–1052 [Google Scholar]

[CR18] Miano AC, Augusto PED (2018) The hydration of grains: a critical review from description of phenomena to process improvements. Compr Rev Food Sci Food Saf 17(2):352–370 [DOI] [PubMed] [Google Scholar]

[CR19] Mohammadi F, Marti A, Nayebzadeh K, Hosseini SM, Tajdar-Oranj B, Jazaeri S (2021) Effect of washing, soaking and pH in combination with ultrasound on enzymatic rancidity, phytic acid, heavy metals and coliforms of rice bran. Food Chem 334:127583 [DOI] [PubMed] [Google Scholar]

[CR20] Mudgal S, Singh N (2024). Effect of parboiling treatment times on the physicochemical, cooking, textural, and pasting properties and amino acid, phenolic, and sugar profiles of germinated paddy rice from different rice varieties. J Food Sci [DOI] [PubMed]

[CR21] Mudgal S, Singh N (2022) Diversity in phenolics, amino acids, rheology and noodles glycemic response of brown rice from non-basmati and basmati rice. Food Res Int 158:111500 [DOI] [PubMed] [Google Scholar]

[CR22] Oh SH, Soh JR, Cha YS (2003) Germinated brown rice extract shows a nutraceutical effect in the recovery of chronic alcohol-related symptoms. J Med Food 6(2):115–121 [DOI] [PubMed] [Google Scholar]

[CR23] Oliveira MEAS, Coimbra PPS, Galdeano MC, Carvalho CWP, Takeiti CY (2022) How does germinated rice impact starch structure, products and nutritional evidences?—A review. Trends Food Sci Technol 122:13–23 [Google Scholar]

[CR24] Pal P, Singh N, Kaur P, Kaur A, Virdi AS, Parmar N (2016) Comparison of composition, protein, pasting, and phenolic compounds of brown rice and germinated brown rice from different cultivars. Cereal Chem 93(6):584–592 [Google Scholar]

[CR25] Prabhakar BN, Suneetha WJ, Devi SS, Shreeja K (2021) Effect of germination on nutritional composition of common buckwheat (Fagopyrum esculentum Moench). Int Res J Pure Appl Chem 22(1):1–7 [Google Scholar]

[CR26] Sandhu RS, Singh N, Kaler RSS, Kaur A, Shevkani K (2018) Effect of degree of milling on physicochemical, structural, pasting and cooking properties of short and long grain Indica rice cultivars. Food Chem 260:231–238 [DOI] [PubMed] [Google Scholar]

[CR27] Sibian MS, Saxena DC, Riar CS (2017) Effect of germination on chemical, functional and nutritional characteristics of wheat, brown rice and triticale: a comparative study. J Sci Food Agric 97(13):4643–4651 [DOI] [PubMed] [Google Scholar]

[CR28] Singh N, Nakaura Y, Inouchi N, Nishinari K (2007) Fine structure, thermal and viscoelastic properties of starches separated from Indica rice cultivars. Starch-Stärke 59(1):10–20 [Google Scholar]

[CR29] Su D, Sultan F, Zhao NC, Lei BT, Wang FB, Pan G, Cheng FM (2014) Positional variation in grain mineral nutrients within a rice panicle and its relation to phytic acid concentration. J Zhejiang Univer Sci B 15(11):986 [DOI] [PMC free article] [PubMed] [Google Scholar]

[CR30] Xia Q, Tao H, Li Y, Pan D, Cao J, Liu L, Zhou X, Barba FJ (2020) Characterizing physicochemical, nutritional and quality attributes of wholegrain L. subjected to high intensity ultrasound-stimulated pre-germination. Food Control 108:106827 [Google Scholar]

[CR31] Zhang Y, Zhao T, Shen J, Wang X (2016) Study on effect of ultrasonic treatment on GABA accumulation and antioxidant capacity in germinated brown rice. Sci Technol Food Ind 37(2):130–133 [Google Scholar]

PERMALINK

Impact of ultrasonication on the physicochemical, pasting, amino acid, mineral, phenolic, and sugar profile of germinated brown rice from various varieties

Swasti Mudgal

Narpinder Singh

Abstract

Supplementary Information

Introduction

Materials and methods

Material and sample preparation

Proximate analysis

Phenolics extraction and analysis

Pasting properties

Mineral and phytic acid composition

Sugar profile by HPLC-PAD

Amino acid composition

Statistical analysis

Results and discussion

Proximate composition

Table 1.

Alpha-amylase activity and total starch

Table 2.

Pasting properties

Fig. 1.

Mineral composition

Table 3.

Phytic acid

Sugar profile by IC

Table 4.

Polyphenolic profile by HPLC

Table 5.

Amino acid composition

Table 6.

Conclusion

Supplementary Information

Acknowledgements

Author contributions

Funding

Availability of data and material

Code availability

Declarations

Conflict of interest

Ethical approval

Consent to participate

Consent for publication

Footnotes

References

Associated Data

Supplementary Materials

Data Availability Statement

ACTIONS

PERMALINK

RESOURCES

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