Skip to main content
NCBI home page
Journal of Food Science and Technology logoLink to Journal of Food Science and Technology
. 2022 Jan 11;59(9):3474–3481. doi: 10.1007/s13197-021-05337-5

Development of rice analogues fortified with iron, folic acid and Vitamin A

Ambrish Ganachari 1,✉, Udaykumar Nidoni 2, Sharanagouda Hiregoudar 2, K T Ramappa 2, Nagaraj Naik 2, S Vanishree 3, P F Mathad 2
PMCID: PMC9304495  PMID: 35875226

Abstract

Fortified rice analogues were developed utilising the broken-rice fortified with selected micronutrients like iron, folic acid and Vitamin A. The purpose of this study was to investigate the feasibility of fortifying rice analogues with micronutrients and retention after extrusion and cooking. Cold extruder operated at 55 rpm screw speed and 1.5 kg/h feed rate was used for the study. The composite flour prepared using broken-rice flour, sodium alginate (1%), water (30%) and micronutrient mix was extruded through rice shaped die at barrel temperature of 60 °C. The level of fortifying nutrient ready mix (FNRM) was statistically optimised based on retention of nutrients after extrusion and cooking. The retention results for iron was observed to be 73.3 to 91.3 per cent after cooking whereas folic acid and Vitamin A being sensitive to processing and culinary operations were 44.2 to 60.4 and 10.1 to 12.4 per cent, respectively. Statistical optimisation resulted 150 per cent of FNRM could supply nutrient levels nearing the standards with the desirability of 0.835. The production cost was calculated as Rs.53.50 per kg whereas, increase in the cost of raw rice mixed with fortified analogues @ 1:50 ratio was about Rs.1.00 per kg with benefit–cost ratio of 1.22:1.

Keywords: Rice analogue, Fortified rice analogue, Extruded rice and rice-like grains

Introduction

Rice is one of the leading food crops and sustains two-third of the world’s population, supplying 20% of the world’s dietary energy (Choi et al. 2010). Despite rice being a primary food, rice is low in protein and high in starch. Unpolished rice is a rich source of vitamins B1, B6, E, and niacin (USDA 2012) whereas the majority (75–90%) of these vitamins are removed during polishing (Muthayya et al. 2012; Steiger et al. 2014). Population that subsists on rice are at high risk of micronutrient (mineral and vitamin) deficiency (Muthayya et al. 2012). These deficiencies of micronutrient affected approximately 2 billion people worldwide, with main cause being inadequate dietary micronutrient intake that is linked to low dietary diversity (Burchi et al. 2011). This type of micronutrient malnutrition is often unnoticed and is called “hidden hunger”. This type of malnutrition is not the overt and obvious hunger of poor people who cannot afford to eat (Yoo et al. 2013). Most of the people affected do not show the physical symptoms usually associated with hunger and nutrient deficiency (FAO 2013). Hence, malnutrition can be responsible for more ill-health than any other causes and good health is possible only with supply of proper nutrition.

This type of hidden hunger could be prevented and reduced by improving the micronutrient status in the daily diet of the population. Globally there are three nutritional intervention strategies are in use to combat micronutrient malnutrition. (i) Enhancing the intake of foods rich in micronutrients by dietary diversification, (ii) supplementation of target micronutrients, and (iii) fortification of micronutrients in the commonly consumed food items (Lee et al. 2000). The fortified foods consumed by the majority of population have evidenced to be a good strategy for reducing the risk of micronutrient malnutrition (De Pee 2014). Rice is an excellent staple food for delivering micronutrients to the large number of people and has the potential to significantly alleviate micronutrient deficiencies (Steiger et al. 2014). However, there are plenty of opportunities for fortifying the rice with vitamins and minerals using various techniques and add these micronutrients to milled rice.

One approach is to produce fortified “faux” rice kernels using extrusion technology (Dexter 2012) in which the micronutrients are embedded and consequently do not separate from the rice grains during washing and cooking (Steiger 2010). Food extrusion is a process in which food material is forced to flow, under one or more varieties of conditions through a die that is designed to form ingredients (Riaz 2000). Looking at the suitability and ease of operation, the cold extrusion process could be an effective method to prevent the loss of fortified nutrients due to negligible rise in temperature during the production process. The rice analogues thus produced using extrusion process are blended with natural rice (at a 1:200 to 1:50 ratio) to produce fortified rice (Alavi et al. 2008). The nutrients added in the extruded fortified rice kernels are effectively protected during washing and cooking. The process uses low cost broken rice as raw material and kernels can be made to the specific requirements of size, shape, colour and nutrient content to resemble the raw rice with which the fortified rice kernels are blended. Fortification of rice analogues would allow the consumers to get benefited without making major changes in their dietary habits (Kunz 2009; Steiger et al. 2014) reducing hidden hunger. Hence, the aim of the study was therefore to optimize the concentration of the nutrient ready-mix to be added to composite flour so as to maintain target levels of iron, zinc, and vitamin A in the cooked rice.

Material and methods

Raw materials

The broken rice (BPT 5204) was procured from M/s. Radhe Agro Industries, Raichur and the chemicals and reagents for analysis were purchased from M/s. SDFCL-SD Fine Chemicals, Mumbai. The fortification nutrient ready mix (FNRM) was supplied by M/s. Hexagon Nutrition Pvt. Ltd., Nashik, Maharastra. The rice broken were ground using a hammer mill and sieved manually using 150 µ sieve to obtain flour of uniform particle size (Patel et al. 2001).

Fortification

The micronutrients were added to the flour in the form of a ready-mix (FNRM) containing Iron, Folic acid and Vitamin A concentrations of 117.50 g, 0.333 g and 6.937 MIU per kg of ready mix. The target iron, folic acid and Vitamin A concentrations were set at 35.25 mg, 100 µg and 20.81 MIU per kg of extrusion flout. The concentration of the final fortified rice analogues was mixed with raw rice at a ratio of 1:50 to obtain the fortified rice as per the regulatory (FSSAI 2006) and market requirements (Alavi et al. 2008). Hence, the nutrient content of fortified rice analogues would be 50 times more compared to the recommendation. Based on the nutrient content in the premix and the regulatory recommendations, the quantity of FNRM per kg of composite flour was 300 mg. This could give 35.25 mg of iron, 100 μg of folic acid, and 20.81 MIU of Vitamin A.

Process for the production of fortified rice analogue

Fortified rice analogues were produced by the extrusion process using cold extruder (La Monferrina, Dolly mini, Italy). The cold extruder is a single screw extruder consisted of a stainless steel screw having 3:1 barrel length to diameter ratio with uniform pitch. It was powered by a 2.25 kW electrical motor through a speed reduction system. The extruder operating conditions were fixed at 55 rpm screw speed and 1.5 kg/h feed rate. The temperature profile in the barrel zone towards the rice-shaped die was 60 °C.

The rice analogues with desirable internal and apparent good texture were prepared using broken rice flour as base material along with sodium alginate @ 1% (Cox and Cox 1993) as a binding agent, micronutrient ready mix and water. The flour mix was tempered by adding a predetermined amount of water (35.7 ml/100 g) to bring the moisture content to 30 per cent wet basis and mixing (30 min.) for equilibrium (Yogeshwari et al. 2019). After obtaining the dough of required consistency, the extruder was operated to produce the rice analogues with the desired size using a cutter blade attached at the outlet of the die. The extrudates were collected, cooled at room temperature and dried to less than 15% moisture content on wet basis (Steiger 2010) in a tray drier at 40 °C for 1 h (Patel et al. 2001) before packing.

Experimental design

The anticipated losses of the micronutrients during extrusion and cooking of the fortified rice analogues were not known and hence arbitrarily fixed as 25 and 50 per cent and the levels on nutrients and treatment combinations were finalized are presented in Table 1 (Alavi et al. 2008; Kuong et al. 2016). The retention of nutrients in the various treatments was statistically compared with the unfortified rice analogues after extrusion and cooking. The experiments were designed according to the general factorial design. The numerical optimization was carried out using Design-Expert software 7.7.0 (Statease Inc., Minneapolis, USA) for the level of fortification as an independent variable at three levels. The dependent variables/responses selected for optimization process were the retention of nutrients.

Table 1.

Treatment combinations for optimization of nutrient fortification

Treatments Nutrient fortification levels
T0 Control
T1 100% FNRM
T2 125% FNRM
T3 150% FNRM
Open in a new tab

FNRM Fortification nutrient ready mix

Iron content

The Iron content was measured using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) (PerkinElmer Inc. NexIONTM 300, USA). For measurement of metals the internal standard used was distilled water, nitric acid and indium which also served as the diluent. Depending on the sample type, 5 mL of internal standard was added to a test tube along with 10–500 µL of the sample. This mixture was vortexed for 5 min. and then loaded into the auto sampler tray. One milligram of ground broken rice flour sample with 0.5 mL of hydrogen peroxide and 7 mL of concentrated nitric acid was added to the digestion flask and the sample was digested in a microwave digester (Perkin Elmer Inc. MARS6, USA). Digested samples were diluted to 50 mL with distilled water and filtered. A 2% nitric acid which was super pure and standard was made up of specific element with concentrations of 0.1, 0.5 and 1.0 ppm was considered as blank, standards and samples were injected into the ICP-MS. Based on the mass by charge (m/Z) of an element, the software (Syngistix version 1.1) would give the concentration of element (Malassa et al. 2013).

Folic acid content

The folic acid was extracted from samples according to the method described in AOAC 1990. The sample powder (2 g) was added in 25 mL of H2SO4 (0.1 N) solution and incubated for 30 min at 121 °C. The sample contents were cooled and pH was adjusted to 4.5 by addition of 2.5 M sodium acetate and 50 mg of enzyme Takadiastase. The prepared solution was stored at 35 °C overnight. The mixture was filtered through a Whatman No. 4 filter paper and diluted using 50 mL of water and filtered again through a micropore filter (0.45 μm). The HPLC system was injected with 20 µl of the filtrate. The vitamin content was quantified by comparing the standards. Standard stock solutions for folic acid and thiamine were prepared as reported by Ringling and Rychlik (2013). Chromatographic separation was achieved on a reversed-phase (RP) HPLC column (C18; 250 × 4.6 mm i.d., 5 μm) at a flow rate of 0.5 mL/min through the isocratic delivery of mobile phase (A/B 33/67; A: MeOH, B: 0.023 M H3PO4, pH = 3.54). Ultraviolet (UV) absorbance was recorded at 270 nm at room temperature (Sami et al. 2014).

Vitamin A content

Vitamin A was measured using the procedure explained by Sami et al. (2014) and Jun et al. (2007). The sample powder of 10 g was added with one g of pyrogallic acid, 70 mL of ethanol and 30 mL (50%) of KOH along with stirring and refluxed for 40 min using a water bath at 50 ± 2 °C. Extracts were obtained three times using various ether concentrations (50, 30 and 20 mL). The extracts obtained were neutralised with distilled water and dehydrated using anhydrous sodium sulfate. Further, the extract was concentrated to approximately 5 mL by using a water bath (50 ± 2 °C), diluted to 10 mL by using methanol, filtered using a 0.45 μm membrane, and finally subjected to HPLC analysis. Reverse-phase HPLC analysis was performed with the Agilent 1100 Series HPLC system, using a diode array detector. The column used for fat-soluble vitamin A was Agilent Eclipse XDB-C18 (5 μm, 4.6 × 150 mm). The solvent used was methanol and UV detection was recorded at 325 nm. Based on isocratic elution vitamin A was separated maintaining the solvent flow rate of 1 mL/min. The sample extract of 20 µl was injected into the HPLC column. Fat-soluble vitamins were identified by comparing their retention times with those of authentic standards. The complete procedure was carried out in subdued light conditions.

Economics of rice analogue production

The significant part of fortified rice analogue development depends not only on their legal status, expected bioavailability, stability and sensory acceptability but also on the cost-effectiveness. The cost of production for rice analogues was calculated using two importance cost concepts viz., fixed costs and variable costs.

Results and discussion

Retention of iron after extrusion and cooking

The retention of Iron in the fortified rice analogues after extrusion and cooking is presented in Table 2. It can be observed that, retention of Iron in extruded and cooked fortified rice analogues ranged from 1740.35 ± 10.31 (96.1%) to 2664.40 ± 20.71 mg/kg (98.9%) and 1653.5 ± 1.24 to 1973.50 ± 9.91 mg/kg, respectively compared to unfortified rice analogue with 49.20 ± 0.21 and 14.80 ± 0.20 mg/kg, respectively when total iron (initial and added) content present in the composite flour is considered as base. The analysis of variance showed the significant difference in the iron content of different treatments after extrusion and cooking (P < 0.05). The total retention of iron after extrusion and cooking was observed to be highest in T1 and the lowest in T3 treatment. It shows that there was a negligible effect of cold extrusion on the Iron retention whereas, for cooked rice, these values were comparatively lower. This indicated that little iron was lost during extrusion and cooking which was expected since iron does not degrade as easily as the vitamins (Yogeshwari et al. 2019) and minor variations in the distribution of the nutrients (Ayoub et al. 2013). Similar results iron retentions were recorded by Ayoub et al. (2013) with 95–99% under high and low shear extrusion during the development of fortified extruded rice and Wieringa et al. (2014) with 79–100% retention in the cold extruded fortified rice analogues cooked by different methods. Yogeshwari et al. (2019) also reported 99% retention of for micronutrient fortified extruded rice analogues.

Table 2.

Retention of iron content in extruded and cooked fortified rice analogues

Treatments Iron
Level of fortification Extruded rice (mg/kg) Extrusion retention (%) Cooked rice (mg/kg) Cooking retention (%) Total retention (%)
T0 0.000 49.20 ± 0.21 - 14.80 ± 0.20 -
T1 1762.50 1740.35 ± 10.31 96.1 1653.50 ± 1.24 95.0 91.3
T2 2203.13 2211.68 ± 1.42 98.2 1856.80 ± 6.15 84.0 82.4
T3 2643.75 2664.40 ± 20.71 98.9 1973.50 ± 9.91 74.1 73.3
CD@1% 2.402 1.413
SE(m) ±  0.771 0.454
CV 0.093 0.066
F value 1189.93 571.43
Significance S S
R-squared 0.99623 0.99218
Adj. R-squared 0.99539 0.99045
Pred. R-squared 0.99330 0.98610
Open in a new tab

The "Pred. R-Squared" are in reasonable agreement with the "Adj. R-Squared"

*S- Significant

T0 – Control (unfortified), T1- 100% FNRM; T2- 125% FNRM; T3- 150% FNRM

Retention of folic acid after extrusion and cooking

The folic acid retention in extruded and cooked fortified rice analogues was observed to be ranged from 4.86 ± 0.04 to 7.23 ± 0.03 mg/kg and 2.21 ± 0.04 to 4.53 ± 0.04 mg/kg, respectively as shown in Table 3. The content was not detected in unfortified rice analogue might be due to levels below the quantification limit. The folic acid content in the extruded fortified rice analogue samples were close to the target concentrations might be due to the natural presence in rice flour mixture (Wieringa et al. 2014). The retention of folic acid levels in cooked fortified rice analogues was lower due to losses during cooking and method of preparation resulted in thermal degradation and leaching into cooking water (Leskova et al. 2006). The per cent retention in the extrusion and cooking were found to be 94.4 to 97.6 and 45.3 to 64.0 and the total retention (initial and added) of folic acid after extrusion and cooking was found to be 44.2 to 60.4 per cent shown in Table 3. Statistical analysis revealed significant differences in the folic acid content between various treatments after extrusion and cooking (P < 0.05). Results recorded by Leskova et al. (2006) also showed 40% retention of folates during culinary treatment of legumes and Wieringa et al. (2014) with 61–97% retention in the cold extruded fortified rice analogues cooked by different methods.

Table 3.

Retention of folic acid content in extruded and cooked fortified rice analogues

Treatments Folic acid
Level of fortification Extruded rice (mg/kg) Extrusion retention (%) Cooked rice (mg/kg) Cooking retention (%) Total retention (%)
T0 0 [< LOQ-10.0] - [< LOQ-10.0] - -
T1 5.00 4.88 ± 0.03 97.6 2.21 ± 0.04 45.3 44.2
T2 6.25 6.01 ± 0.02 96.2 3.45 ± 0.07 57.4 55.2
T3 7.50 7.08 ± 0.04 94.4 4.53 ± 0.04 64.0 60.4
CD@1% 0.092 0.149
SE(m) ±  0.03 0.048
CV 1.316 3.749
F value 1040.64 440.76
Significance S S
R-squared 0.99569 0.98989
Adj. R-squared 0.99473 0.98764
Pred. R-squared 0.99234 0.98203
Open in a new tab

The "Pred. R-Squared" are in reasonable agreement with the "Adj. R-Squared"

*S- Significant, LOQ: Limit of quantification

T0 – Control (unfortified), T1- 100% FNRM; T2- 125% FNRM; T3- 150% FNRM

Retention of Vitamin A after extrusion and cooking

The Vitamin A retention after extrusion and cooking ranged from 12,365.75 ± 61.29 to 16,726.5 ± 54.78 mcg RE/kg and 3878.75 ± 18.18 to 4713.75 ± 64.75 mcg RE/kg, respectively whereas, it could not detect in unfortified rice analogue due to levels below the quantification limit. The results of the statistical analysis showed a significant difference in the Vitamin A content of various treatments after extrusion and cooking (P < 0.05). From Table 4 it is also observed that the extrusion and cooking significantly reduce the Vitamin A fortified rice analogues (Lee et al. 2000 and Pinkaew et al. 2012). It was also reported by Leskova et al. (2006) that Vitamin A is quite stable under an inert atmosphere, but it rapidly losses its activity when heated in the presence of oxygen, especially at higher temperatures (Wieringa et al. 2014). The results of all samples showed vitamin A concentrations below the fortified level (values expected based on fortification levels). The per cent retention in the extrusion and cooking were found to be 35.7 to 39.6 and 28.2 to 31.4 per cent and the total retention (initial and added) of Vitamin A due to extrusion and cooking was found to be 10.1 to 12.4 per cent as shown in Table 4. The results of Murphy et al. (1992) for Vitamin A fortified rice showed retention of 46–94% after cooking. Ayoub et al. (2013) recorded relatively higher retention levels (44%) in fortified, extruded, artificial rice grains whereas Wieringa et al. (2014) with 6.3–67.6% retention in the cold extruded fortified rice analogues cooked by different methods.

Table 4.

Retention of Vitamin A content in extruded and cooked fortified rice analogues

Treatments Vitamin A
Level of fortification Extruded rice (mcg RE/kg) Extrusion retention (%) Cooked rice (mcg RE/kg) Cooking retention (%) Total retention (%)
T0 0 [< LOQ-10.0] [< LOQ-10.0] - -
T1 31,250 12,365.75 ± 61.29 39.6 3878.75 ± 18.18 31.4 12.4
T2 39,062.5 15,166.25 ± 47.93 38.8 4301.25 ± 37.60 28.4 11.0
T3 46,875 16,726.5 ± 54.78 35.7 4713.75 ± 64.75 28.2 10.1
CD@1% 148.237 120.035
SE(m) ±  47.582 38.529
CV 0.86 2.391
F value 1617.18 88.07
Significance S S
R-squared 0.99722 0.95138
Adj. R-squared 0.99661 0.94058
Pred. R-squared 0.99507 0.91357
Open in a new tab

The "Pred. R-Squared" are in reasonable agreement with the "Adj. R-Squared"

*S- Significant, LOQ: Limit of quantification

T0 – Control (unfortified), T1- 100% FNRM; T2- 125% FNRM; T3- 150% FNRM

Optimisation of nutrient fortification

Numerical optimization was applied to determine the optimal nutrient treatment retaining required levels of nutrients in the cooked fortified rice analogues. The values of all the responses at operating conditions were converted to a desirability function configured as 0 and 1 for minimum and maximum values, respectively (Krishnaiah et al. 2012). The optimum nutrient treatment suggested by the software for the rice analogues was 150% FNRM with the desirability of 0.835 as shown in Fig. 1.

Fig. 1.

Fig. 1

Open in a new tab

Desirability graph for optimum nutrient treatment in the production of fortified rice analogues

Economics of fortified rice analogues production

The cost involved in the production of fortified rice analogue was calculated to be Rs. 53.50 per kg whereas, increase in the cost of raw rice after mixing with fortified analogues @ 1:50 ratio was about Rs. 1.00 per kg. The benefit–cost ratio was worked out to be 1.22:1. The fortification process involves simple operations and minimum additional investment is needed in particularly rice consuming states as a whole to accomplish fortification to combat the malnutrition. Given the present technology, a set of equipment for blending fortified rice analogues with raw rice could be accomplished easily in any rice mill.

Conclusion

The results of the study revealed that fortified rice analogues enriched with iron, zinc and vitamin A could be produced utilising the broken rice as the base material in cold extrusion technology. The optimisation results showed the fortifying nutrient ready mix (FNRM) of 150% could be added to obtain target levels of the nutrients in the cooked rice with the highest statistical desirability. The cost calculations also revealed that the fortified rice could be produced with lower cost and economically affordable by all the categories of the people. The cost of production of fortified rice analogues was calculated to be Rs. 54 per kg with the cost of fortified rice after mixing with raw rice @1:50 was Rs.1 per kg higher than raw rice. The benefit–cost ratio was worked out to be 1.22:1.

Acknowledgements

The authors would like to thank; University of Agricultural Sciences (UAS) Raichur for providing facilities for undertaking research. AICRP on PHET, CIPHET, Ludhiana for providing the financial assistance. M/s. Hexagon Nutrition Pvt. Ltd. Nasik for providing the nutrients for the research

Abbreviations

AOAC

Association of official analytical chemists

FAO

Food and agriculture organization

FNRM

Fortifying nutrient ready mix

FSSAI

Food safety and standards authority of India

H3PO4

Orthophosphoric acid

HPLC

High performance liquid chromatography

ICP-MS

Inductively coupled plasma mass spectroscopy

KOH

Potassium hydroxide

m/Z

Mass/charge ratio

MeOH

Methyl Alcohol

MIU

Million international units

RE

Retinol equivalents

RP

Reversed-phase

RP-HPLC

Reverse phase high performance liquid chromatography

USDA

United states department of agriculture

UV

Ultra violet

Author contributions

Dr. Ambrish Ganachari was responsible for conceiving the idea, carried out the work and wrote the manuscript, while Dr. Udaykumar Nidoni and Dr. Sharangouda H supervised the work and corrected the manuscript; Dr. Ramappa KT and Dr. Mathad PF analysed the data statistically and corrected the manuscript; Dr. Nagaraj Naik and Dr. Vanishree, S have analysed the quality parameters and corrected the manuscript.

Funding

This work was supported by AICRP on PHET, CIPHET, Ludhiana.

Availability of data and material

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Code availability

Not applicable.

Declarations

Conflict of interest

The authors declare that they have no competing interests.

Footnotes

Publisher's Note

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

References

  1. Alavi S, Bugusu B, Cramer G, Dary O, Lee T, Martin L, Mc Entire J, Wailes E (2008) Rice fortification in developing countries: a critical review of the technical and economic feasibility. Washington (DC): A2Z Project, Academy for Educational Development. https://pdf.usaid.gov/pdf_docs/pnaeb101.pdf. Accessed 28 March 2018.
  2. Ayoub A, Liu Y, Miller DD, Rizvi SSH. The effect of low shear on the development of fortified extruded rice products. Starch Stärke. 2013;65(5–6):517–526. doi: 10.1002/star.201200101. [DOI] [Google Scholar]
  3. Burchi F, Fanzo J, Frison E. The role of food and nutrition system approaches in tackling hidden hunger. Int J Environ Res Public Health. 2011;8(2):358–373. doi: 10.3390/ijerph8020358. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chang HJ, Gan BZ, Liu CY, Liang HG, Yu QL. Long RJ (2007) Study on content determination of Vitamin A and E in white yak’s milk by HPLC. J Gansu Agric Univ. 2007;2:108–111. [Google Scholar]
  5. Choi HJ, Chang JL, Cho EJ, Choi SJ, Moon TW. Preparation, digestibility, and glucose response in mice of rice coated with resistant starch type 4 using locust bean gum and agar. Int J Food Sci Technol. 2010;45(12):2612–2621. doi: 10.1111/j.1365-2621.2010.02434.x. [DOI] [Google Scholar]
  6. Cox JP, Cox JM (1993) Cohesive vegetable product and process for manufacture. United States Patent, 5252351
  7. De Pee S. Proposing nutrients and nutrient levels for rice fortification. Ann NY Acad Sci. 2014;1324(1):55–66. doi: 10.1111/nyas.12478. [DOI] [PubMed] [Google Scholar]
  8. Dexter PB (2012) Rice fortification for developing countries. Fayetteville, Ark, USA. OMNI/USAID. http://pdf.usaid.gov/pdf_docs/PNACD279.pdf. Accessed 25 June 2019
  9. FAO Food and Agriculture Organization of the United Nations (2013) The State of Food and Agriculture, Rome. http://bit.ly/KAn84P. Accessed 14 May 2019
  10. Food Safety and Standards Authority of India (FSSAI) (2006) Standards for fortification of foods-2017. https://www.fssai.gov.in/upload/uploadfiles/files/Gazette_Notification_Food_Fortification_10_08_2018.pdf. Accessed 4 May 2019
  11. Krishnaiah D, Bono A, Sarbatly R, Nithyanandam R, Anisuzzaman SM. Optimisation of spray drying operating conditions of Morinda citrifolia L. fruit extract using response surface methodology. J King Saud Univ Engg Sci. 2012;27(1):26–36. [Google Scholar]
  12. Kunz R (2009) A breakthrough in rice fortification. http:// www.buhlergroup.com/global/downloads/Breakthrough_in_Rice_Fortification.pdf. Accessed 29 Nov 2018
  13. Kuong K, Laillou A, Chea C, Chamnan C, Wieringa BJ, FT, Stability of Vitamin A, iron and zinc in fortified rice during storage and its impact on future national standards and programs—Case study in Cambodia. Nutrients. 2016;8(1):1–9. doi: 10.3390/nu8010051. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Lee J, Hamer ML, Eitenmiller RR. Stability of retinyl palmitate during cooking and storage in rice fortified with ultrarice fortification technology. J Food Sci. 2000;65(5):915–919. doi: 10.1111/j.1365-2621.2000.tb13612.x. [DOI] [Google Scholar]
  15. Leskova E, Kubikova J, Kovacikova E, Kosicka M, Porubska J, Holcikova K. Vitamin losses: retention during heat treatment and continual changes expressed by mathematical models. J Food Compost Anal. 2006;19(4):252–276. doi: 10.1016/j.jfca.2005.04.014. [DOI] [Google Scholar]
  16. Malassa H, Al-Qutob M, Al-Khatib M, Al-Rimawi F. Determination of different trace heavy metals in ground water of south west bank palestine by ICP/MS. J Environ Prot. 2013;4(1):818–827. doi: 10.4236/jep.2013.48096. [DOI] [Google Scholar]
  17. Murphy PA, Smith B, Hauck C, O’Connor K. Stabilization of vitamin A in a synthetic rice premix. J Food Sci. 1992;57(2):437–439. doi: 10.1111/j.1365-2621.1992.tb05511.x. [DOI] [Google Scholar]
  18. Muthayya S, Hall J, Bagriansky J, Sugimoto J, Gundry D, Matthias D, Prigge S, Hindle P, Moench-Pfanner R, Maberly G. Rice fortification: an emerging opportunity to contribute to the elimination of vitamin and mineral deficiency worldwide. Food Nutr Bull. 2012;33(4):296–307. doi: 10.1177/156482651203300410. [DOI] [PubMed] [Google Scholar]
  19. Patel NC, Das SK, Bal S. Process and machine for production of rice analog from broken rice. ASAE Annual International Meeting, Sacramento Convention Center Sacramento, California, USA. 2001 doi: 10.13031/2013.3986. [DOI] [Google Scholar]
  20. Pinkaew S, Wegmuller R, Hurrell R. Vitamin A stability in triple fortified extruded, artificial rice grains containing iron, zinc and vitamin A. Int J Food Sci Technol. 2012;47(10):2212–2220. doi: 10.1111/j.1365-2621.2012.03091.x. [DOI] [Google Scholar]
  21. Riaz MN. Extruders in food applications. Boca Raton, FL: CRC Press Inc; 2000. [Google Scholar]
  22. Ringling C, Rychlik M. Analysis of seven folates in food by LC-MS/MS to improve accuracy of total folate data. Eur Food Res Technol. 2013;236(1):17–28. doi: 10.1007/s00217-012-1849-x. [DOI] [Google Scholar]
  23. Sami R, Li Y, Qi B, Wang S, Zhang Q, Han F, Ying M, Jing J, Jiang L. HPLC analysis of water-soluble Vitamins (B2, B3, B6, B12, and C) and Fat-Soluble Vitamins (E, K, D, A, and β-Carotene) of Okra (Abelmoschus esculentus) J Chem. 2014 doi: 10.1155/2014/831357. [DOI] [Google Scholar]
  24. Steiger G, Muller-Fischer N, Cori H, Conde-Petit B. Fortification of rice: Technologies and nutrients. Ann NY Acad Sci. 2014;1324(1):29–39. doi: 10.1111/nyas.12418. [DOI] [PubMed] [Google Scholar]
  25. Steiger G (2010) Reconstituted rice kernels and processes for their preparation. https://patents.google.com/patent/WO2010020640A1/en. Accessed 29 Nov 2018
  26. UNIFEF . State of the World’s Children. New York: UNICEF; 1991. [Google Scholar]
  27. US Department of Agriculture (USDA) (2012) Food composition tables. National nutrient database for standard reference release 26. http://ndb.nal.usda.gov/ndb/search/list. Accessed 28 Nov 2018
  28. Wieringa FT, Laillou A, Guyondet C, Jallier V, Moench-Pfanner R, Berger J. Stability and retention of micronutrients in fortified rice prepared using different cooking methods. Ann NY Acad Sci. 2014;1324(1):40–47. doi: 10.1111/nyas.12497. [DOI] [PubMed] [Google Scholar]
  29. Yogeshwari R, Hemalatha G, Vanniarajan C, Saravanakumar R, Kavithapushpam A. Development of micronutrient fortified extruded rice analogues. Eur J Nutr Food Saf. 2019;9(1):1–11. [Google Scholar]
  30. Yoo J, Alavi S, Adhikari K, Haub MD, Aberle RA, Huber G. Rice shaped extruded kernels: physical, sensory, and nutritional properties. Int J Food Prop. 2013;16(2):301–321. doi: 10.1080/10942912.2010.495042. [DOI] [Google Scholar]

Associated Data

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

Data Availability Statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Not applicable.

Articles from Journal of Food Science and Technology are provided here courtesy of Springer

RESOURCES