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. 2021 Nov 21;59(9):3349–3358. doi: 10.1007/s13197-021-05318-8

Bioactive compounds recovered from apple pomace as ingredient in cider processing: monitoring of compounds during fermentation

Laís Benvenutti 1, Débora Gonçalves Bortolini 1, Thaís Estéfane Fischer 2, Danianni Marinho Zardo 1, Alessandro Nogueira 1, Acácio Antonio Ferreira Zielinski 3, Aline Alberti 1,✉
PMCID: PMC9304537  PMID: 35875229

Abstract

The apple pomace—industrial residue of apple beverages manufacture—presents 42–58% of the phenolic content of fresh fruit. As the phenolic composition influences the quality of ciders, it is very relevant to monitor the evolution of these compounds during the industrial process. Therefore, this research aim was to monitor the cider composition with the addition of phenolic extract from apple pomace during the fermentation. Two treatments, S1 (without extract) and S2 (with added extract), were evaluated during 15 days of fermentation. After 15 fermentation days, the sample S2 presented an increase of 23% in total phenolic compounds and 40% in flavonoids without harm to the fermentation kinetics. Concerning the evolution of monomeric phenolic compounds, the phenolic acids in S1 and S2 presented a similar trend during the fermentation period. Enzymatic hydrolysis reactions resulted in the chlorogenic acid content decreasing, in line with increased levels of caffeic acid. Phloridzin and quercetin glycosides content showed the greatest increase in S2. The final product S2 presented higher antioxidant activity and some sensorial characteristics (astringency, bitterness and colour) were accentuated. This work shows that phenolic compounds added were maintained during the process and it did not prejudice the fermentation reactions. Therefore, this is a good alternative to valorize apple pomace and improve the functional and sensorial quality of the cider.

Keywords: Functional compounds, Industrial residue, Green process, Antioxidant activity, Sensory analysis, Beverage quality

Introduction

Cider is, in most countries, a denomination of the alcoholic fermented beverage derived from apples. The composition of this beverage is based on water, ethanol, sugars, organic acids, polyphenols, and aroma compounds, in proportions that vary depending on the cultivar and the ripening stage of the raw material (Alberti et al. 2016; Symoneaux et al. 2014). The cider quality is related to the composition of apple, especially its polyphenol profile (Alonso-Salces et al. 2004). Beyond conferring bioactive properties, the phenolic compounds are responsible for sensorial characteristics, such as color, bitterness, astringency, and the production of certain aroma compounds (Guo et al. 2018; Ye et al. 2014).

Industrial apple varieties present approximately 2700 mg/kg of total phenolic content (TPC). However, some countries manufacture cider from commercial apples that have an average phenolic concentration of 1022 mg/kg (Van der Sluis et al. 2002; Zardo et al. 2013). Furthermore, after the industrial process of fruit, the must of the apple contains about 30% of the polyphenol content of fresh fruit, mainly due to the retention of compounds in the apple pomace and browning reaction by polyphenol oxidase (PPO) activity (Van der Sluis et al. 2002).

The apple pomace, a low-value by-product from apple beverage, retains 42–58% of the total phenolic content due to hydrophobic interactions and molecular bonds between these compounds and the cell wall of the apple pomace (Van der Sluis et al. 2002). Apple fruit is one of the most popular (84 million tonnes were produced in 2018) and studied fruit in the world (FAOSTAT 2020). There are studies ranging from the evaluation of the ethylene releasing by apple flowers to influencing the ripening stage on the quality of ciders (Alberti et al. 2016; Popa 2019). As part of apple production is processed to juice and cider, a large amount of apple pomace is generated since this by-product represents about 25% of fresh fruit (Barreira et al. 2019). The use of this by-product has been evaluated in chemical, food, and pharmaceutical industries mainly due to its composition rich in polyphenolic, triterpenes, and pectin, conferring technological properties and health benefits such as antioxidant, antimicrobial, anti-inflammatory (Barreira et al. 2019; González-Garcia et al. 2018; Lu et al. 2020).

An economically viable and sustainable new route to preserve the bioactivity of cider, to improve its sensory characteristics, and to valorise its agro-industrial residue can be the recovery of the compounds from apple pomace and application them in the apple must. This approach is based on the circular economy concept that seeks to maintain the value of products as long as possible within the chain, while simultaneously reducing waste production (European Commission 2017). However, it is necessary to control the process because of the phenolic profile is changed during the alcoholic fermentation due to chemical and enzymatic reactions, as well as absorption by yeasts (Samaleh et al. 2008).

Therefore, this work aimed i) to monitor the composition of the cider supplemented with polyphenol-rich extract recovered from apple pomace during fermentation; and ii) to evaluate the effects on the quality of the cider, verifying the potential application of this by-product in the food industry.

Materials and methods

Materials

The experiments were performed using commercial apples of the Fuji variety. The reagents used were: Folin-Ciocalteu, TPTZ (2,4,6-Tri (2-pyridyl)-s-triazine); DPPH (2,2-diphenyl-2-picrylhydrazyl); ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid); and neocuproine (2,9-Dimethyl-1,10-phenanthroline) (Sigma-Aldrich, Steinheim, Germany). Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), sugars and phenolic standards were purchased from Sigma-Aldrich (Steinheim, Germany). All the other solvents were of analytical grade. The aqueous solutions were prepared using ultrapure water (Millipore, Brazil).

Manufacture of apple must and apple pomace

Depectinised apple juice was used as the apple must, that was obtained according to Alberti et al. (2016). The apple pomace was dried using a circulation oven at 50 °C (MARCONI MA-03) until 2% moisture. Subsequently, the pomace was crushed in a mill (IKA WERKE, M20, USA) and sieved (20 and 40 mesh), obtaining particles that ranged from 0.42 to 0.84 mm. The sample was stored in a desiccator at 20 °C (Fig. 1).

Fig. 1.

Fig. 1

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Scheme of apple musts and ciders processing with (S1) and without (S2) the addition of phenolic extract

Extraction of phenolic compounds

The extraction of polyphenolic compounds from the apple pomace was performed by the maceration method using 60% ethanol at 50 °C and a solid-to-solvent ratio of 1:20 (m/V) for 20 min, with subsequent centrifugation (8500×g, 20 min at 4 °C) (HITACHI KOKI Co. Ltd., CR21GII, Japan). The solvent was removed in a rotary vacuum evaporator at 48 ± 2 °C (TECNAL, TE-211, SP, Brazil). The samples were stored at − 18 °C until analysis. The extract to be added to the apple must was freeze-dried (Fig. 1) (TERRONI, LS3000, SP, Brazil).

Cider manufacture

The depectinised apple must was transferred to glass fermenters and was then divided into two samples that were designated S1 and S2 (Fig. 1). The freeze-dried polyphenol-rich extract was added in the S2 apple must until the total flavonoid content increased by 40% (about to 42 mg/L). This value was based on the phenolic content that can be extracted from the volume of apple pomace generated during apple must manufacture.

Both the apple musts were fermented according to Alberti et al. (2016) with Saccharomyces cerevisiae r.f. bayanus (Fermol Reims Champagne, AEB Group, San Polo, Brescia, Italy) at a concentration of 20 g/hL. The alcoholic fermentation process was conducted at 20 °C and monitored according to Santos et al. (2018). Besides, physical–chemical and instrumental characterization was performed after 1, 4, 7, 11, and 15 days of fermentation, giving rise to the sets of samples that were identified as S1 (control sample, without the addition of extract) and S2 (enriched with phenolic extract).

Fermentation monitoring

Viable cell count

The viable cells were counted using a Neubauer chamber according to Bonneu et al. (1991). In sequence, the yeast biomass and cider were separated by centrifugation at 7980×g at 4 °C for fifteen minutes.

pH and acidity

The pH of the samples was determined using a potentiometer (Tecnal, TEC 3-MP, SP, Brazil), and titratable acidity was assessed according to the AOAC (2016) and expressed as malic acid content (g/100 mL).

Phenolic compounds

The total phenolic content (TPC) was determined according to the Singleton and Rossi (1965) method. The absorbances (720 nm) were measured in a spectrophotometer (SHIMADZU, UVmini-1240, Brazil) and the concentrations were obtained from the standard curve (TPC = 1612.90 × absorbance; R2 = 0.9932) of chlorogenic acid (20–200 mg/L).

The total flavonoid content (TFC) analysis was performed according to the Zhishen et al. (1999) method. The data were expressed in milligrams of catechin equivalent from a standard curve (20–200 mg/L; TFC = 420.17 × absorbance; R2 = 0.9981).

The flavanol content (FAC) was determined according to the Broadhurst and Jones (1978) method. The concentrations were obtained by the absorbances (500 nm) of the standard curve of catechin, 20–200 mg/L (FAC = 625 × absorbance; R2 = 0.9978).

For individual phenolic analysis, an aliquot of 10 mL of each sample was freeze-dried and reconstituted by adding 5 mL of 2.5% acetic acid and methanol (3:1 v/v) solution. Each sample was passed through a 0.22 µm nylon syringe filter.

The individual phenolic compounds were determined according to Alberti et al. (2014) using high-performance liquid chromatography (HPLC) system equipped with a quaternary pump (Waters Alliance 2695), degasser and auto-injector, photodiode array detector (Waters PDA 2998), and a Symmetry C18 (4.6 × 150 mm, 3.5 µm; Waters) column. The chromatography data were obtained using Empower® 2 software. The identification and quantification of the compounds were performed by comparing the retention times and spectra of the standards. The flavonol content (FOC) was determined by the sum of the area of the total peaks of quercetin glycosides, which was determined by HPLC according to Alberti et al. (2017).

Antioxidant activity

In vitro antioxidant activities were assessed using the DPPH (Brand-Williams et al. 1995), ABTS (Re et al. 1999), FRAP (Benzie and Strain 1996), and CUPRAC (Apak et al. 2008) methods. The concentration was obtained by comparing the absorbances with the standard curve of trolox of 100–1,000 µmol/L (DPPH = 22.72 × absorbance, R2 = 0.9946; ABTS = 4.48 × absorbance, R2 = 0.9944; FRAP = 1,041.66 × absorbance, R2 = 0.9986; and CUPRAC = 3,333.33 × absorbance, R2 = 0.9969).

Sugar and alcohol content

The sugar and ethanol contents were determined using an HPLC system (Waters Alliance 2695) with a refractive index detector (Waters RI 2414) and Sugar Pak™ column (300 × 6.5 mm i.d.), according to Zielinski et al. (2016).

Colorimetric analysis

The colour analysis was performed using a spectrophotometer (Konica Minolta, CM 5, NJ, USA). The L*, a*, and b* coordinates were used to calculate the Chroma value (colour intensity) and hue angle (tonality), according to Lee et al. (2016).

Sensory analysis

The attributes of the intensity of colour, bitterness, acidity, astringency, and odour quality were evaluated in the ciders after the fifteenth day of fermentation, according to the model adapted from Madrera et al. (2010). All the samples were evaluated in triplicate by eight judges trained in sensory analysis; two men and six women aged 24–41. The evaluation was performed using a nine-point structured scale with 1 representing very weak, 5 moderate, and 9 very strong. The odour quality was evaluated using a nine-point hedonic scale with nine defined as 1—“dislike extremely”, 5 as “indifferent” and 9 as “like extremely”. These analyses were performed after approval by the Research Ethics Committee at the State University of Ponta Grossa (CAAE 62047516.3.0000.0105).

Statistical analysis

The data were shown as the average and standard deviation. The homogeneity of variance of each variable was verified by Levene’s test or the F-test (p > 0.05). The differences between the samples were evaluated by one-way ANOVA test, followed by Fisher’s LSD test or the t-test. Pearson’s coefficients (r) were used to evaluate the correlation between the analysed parameters; the p-value was considered significant below 0.05. All the statistical analyses were performed using Statistica v. 13.3 software (TIBCO Software Inc., USA).

Results and discussion

Extract characterization in terms of phenolic composition

The polyphenol-rich extract recovered from the apple pomace showed chlorogenic acid (212.39 ± 0.22 mg/kg), and flavonoids such as phloridzin (262.99 ± 0.07 mg/kg), hyperoside (188.58 ± 0.17 mg/kg), rutin (102.4 ± 0.1 mg/kg), avicularin (67.74 ± 0.01 mg/kg), quercetin (61.4 ± 0.1 mg/kg), isoquercitrin (2.64 ± 0.07 mg/kg) and reynoutrin (1.72 ± 0.01 mg/kg).

The extractions were performed using 50% ethanol, which is a GRAS (generally recognized as safe) solvent (Renard 2018) and resulted in good efficiency of chlorogenic acid and quercetin glycosides. This solvent results in a higher yield of chlorogenic acid content than the results reported by Suaréz et al. (2010)—about 168.34 mg/kg—using acetone and methanol as the solvent. Besides, it should be highlighted that even as in apple fruit, the phenolic composition of apple pomace varies according to cultivar, the stage of maturation, and the availability of nutrients (Alberti et al. 2017; Guo et al. 2018).

Fermentation monitoring

Kinetic parameters, pH and content of sugar and alcohol

According to the kinetic parameters, the maximum fermentation rates were 19.35 g/Ld and 19.74 g/Ld, for the S1 and S2 samples, respectively. After 15 days, S1 showed a maximum release of CO2 of 74.88 g/L, and S2 showed a maximum of 70.09 g/L. The maximum yeast population was 7.8 × 107 and 6.3 × 107 CFU/mL for S1 and S2, respectively. There were no significant (p > 0.05) differences between the kinetic parameters for the S1 and S2 samples; therefore, the addition of the extract did not influence the fermentation process.

Besides, the addition of the extract did not change the pH and acidity of the apple must (Table 1). Both the treatments showed titratable total acidity that is considered to be low (< 0.45 g/100 mL), which is characteristic of juices from apples destined for fresh consumption.

Table 1.

Concentration of sugars (sucrose, glucose and fructose), ethanol and sorbitol in musts and during fermentation with and without addition of phenolic extract

Samples pH Acidity (g/100 mL) Ethanol
(mL/100 mL)		 Sorbitol
(g/L)		 Sucrose
(g/L)		 Glucose
(g/L)		 Fructose
(g/L)
Apple must S1 3.79b ± 0.01 0.27 g ± 0.01 nd 6.66 g ± 0.06 40.4b ± 0.2 27.9b ± 0.6 75d ± 1
S2 3.80b ± 0.01 0.28 g ± 0.01 nd 7.45c ± 0.03 41.17a ± 0.01 32.9a ± 0.7 82b ± 1
Fermentation time (d) 1 S1 3.63f ± 0.01 0.28f ± 0.01 1.72f ± 0.02 6.44f ± 0.03 2.6c ± 0.3 29.6b ± 0.2 77.5c ± 0.5
S2 3.63f ± 0.01 0.28f ± 0.01 1.83f ± 0.04 7.06d ± 0.09 nd 33.4a ± 0.3 84a ± 1
4 S1 3.68d ± 0.01 0.39e ± 0.01 5.95e ± 0.05 7.05d ± 0.02 nd nd 24.3f ± 0.7
S2 3.71c ± 0.01 0.40d ± 0.01 5.93e ± 0.02 7.44c ± 0.06 nd nd 30e ± 2
7 S1 3.62f ± 0.01 0.40 cd ± 0.01 6.58d ± 0.32 6.93e ± 0.33 nd nd 3.14 h ± 0.02
S2 3.66e ± 0.01 0.42a ± 0.01 7.41b ± 0.02 7.87b ± 0.03 nd nd 5.24 g ± 0.08
11 S1 3.58 g ± 0.01 0.40c ± 0.01 7.23c ± 0.04 7.47c ± 0.05 nd nd nd
S2 3.71c ± 0.01 0.41ab ± 0.01 7.74ª ± 0.02 8.01ª ± 0.02 nd nd 0.42i ± 0.01
15 S1 3.80b ± 0.01 0.40d ± 0.01 7,18c ± 0,09 7.4c ± 0.1 nd nd nd
S2 3.83a ± 0.01 0.41b ± 0.01 7.68ª ± 0.01 7.96ab ± 0.05 nd nd 0.32i ± 0.01
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S1: without addition of the phenolic extract (control); S2: enhanced with phenolic extract; nd: not detected

Different letters in same column indicate statistical difference between the samples according to the Fischer LSD test (p ≤ 0.05)

The sugar and sorbitol content showed significant differences (p < 0.05) between the samples and fermentation days (Table 1). It is possible that the different content of sugar between S1 and S2 musts were derived from the extract because sugars from apple pomace are also solubilized in ethanol solution. The high sugar content in S2 resulted in higher production (p < 0.05) of ethanol than to S1. The glucose and fructose content increased at the beginning of fermentation due to the hydrolysis of sucrose by invertase. After fifteen days of fermentation, only the S2 sample showed a remaining concentration of fructose.

The sorbitol content increased from the first day of fermentation (Table 1). According to Fedor et al. (1960), this compound can be formed from the reduction of glucose and fructose.

Phenolic content and antioxidant activity

The addition of polyphenol-rich extract increased about 23% of total phenolic content (TPC) and 40% of total flavonoid content (TFC) on must of S2 concerning S1 (Table 2). The phenolic compounds decreased during fermentation, mainly because of the oxidative reactions, esterification, and hydrolysis (Ye et al. 2014). Nevertheless, on the fourth day of fermentation, the S2 sample had a total phenolic content that was statistically equal to S1 must.

Table 2.

Phenolic compounds and antioxidant activity during fermentation process of cider without and with addition of phenolic extract

Samples TPC
(mg CAE/L)		 TFC
(mg CATE/L)		 FAC
(mg CATE/L)		 FOC
(mg RUE/L)		 DPPH
(µmol TE/L)		 FRAP
(µmol TE/L)		 ABTS
(µmol TE/L)		 CUPRAC
(µmol TE/L)
Apple must S1 407c ± 10 107b ± 1 90c ± 1 0.90i ± 0.01 467bc ± 38 1161f ± 18 719e ± 9 3299abcd ± 164
S2 500a ± 7 148.9a ± 0.6 111a ± 1 6.60f ± 0.01 803a ± 79 1336d ± 24 979c ± 27 3421ab ± 58
Fermentation time (d) 1 S1 374d ± 11 69.1f ± 0.7 59d ± 1 1.07 h ± 0.01 542bc ± 57 1208f ± 38 605f ± 15 3107de ± 388
S2 458b ± 8 96c ± 1 97b ± 1 13.36a ± 0.01 791a ± 55 1417c ± 14 927 cd ± 75 3132bcd ± 138
4 S1 344e ± 10 56 g ± 1 58.0ef ± 0.9 1.12 g ± 0.01 558b ± 54 1183f ± 38 650f ± 19 3163cde ± 150
S2 421c ± 12 86.4e ± 0.6 92c ± 1 12.00b ± 0.08 821a ± 49 1440bc ± 40 918d ± 20 3379ab ± 185
7 S1 296 h ± 8 55 fg ± 1 58e ± 1 1.05 h ± 0.01 490bc ± 65 1171f ± 58 641f ± 10 2735de ± 215
S2 374d ± 6 90d ± 2 90c ± 1 11.26c ± 0.04 778a ± 43 1483b ± 39 973c ± 42 3429a ± 448
11 S1 317 g ± 17 60f ± 2 56 fg ± 0.7 1.04 h ± 0.01 484bc ± 117 1262e ± 77 643f ± 27 2985e ± 206
S2 338ef ± 7 91d ± 1 90c ± 0.8 8.29d ± 0.02 762a ± 39 1656a ± 49 1154a ± 85 3532a ± 456
15 S1 299 h ± 23 57 fg ± 2 55.7 g ± 0.8 1.07 h ± 0.01 479c ± 87 1184f ± 64 631f ± 24 2890e ± 221
S2 327 fg ± 7 89.3d ± 0.5 90.5c ± 0.4 7.71e ± 0.02 758a ± 58 1445bc ± 30 1058b ± 29 3303abc ± 276
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S1: samples without addition of the extract (control); S2: samples enhanced with phenolic extract; TPC: total phenolic content; TFC: total flavonoids content; FAC: flavanols content; FOC: flavonols content

abc: significant differences between sample of same column, p < 0.05

Overall, no significant differences in phenolic acid levels were observed between S1 and S2 samples (Fig. 2). This fact probably occurred because the extract obtained contains a low concentration of phenolic acids regard to flavonoids, which is the predominant phenolic class from apple pomace (> 84%) due to non-covalent interactions with the cell wall (Le-Bourvellec et al. 2009). During fermentation, the levels of chlorogenic acid decreased and levels of caffeic acid increased in both the samples. According to Madrera et al. (2006), this is the result of the enzymatic hydrolysis of chlorogenic acid. The increase in caffeic acid content is interesting because it is one of the primary phenolic compounds related to the aroma compounds of cider, which influence the odour intensity and quality (Guo et al. 2018). The S1 and S2 samples showed similar concentrations of this phenolic acid, with significant differences (p < 0.05) only on the seventh day of fermentation.

Fig. 2.

Fig. 2

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Individual phenolic compounds of the apple must and their evolution during fermentations days. Note: S1 (without the addition of extract) and S2 (with added extract); Day 1, 4, 7, 11 and 15 represent de fermentation time; abc: different letters represent statistical difference (p < 0.05)

The p-coumaric acid content showed significant differences (p < 0.05) between the samples after the first day of fermentation. At the beginning of fermentation, the concentration of this acid increased, possibly due to the hydrolysis of p-coumaroylquinic acid. This particular acid was not evaluated in the present study; however, it is a compound that is normally detected in ciders (Madrera et al. 2006). From the seventh day of fermentation, there was a significant decrease in the levels of p-coumaric acid, which was probably due to the formation of polyphenols, such as flavonols, by esterification in the presence of ethanol (Samaleh et al. 2008). Furthermore, the presence of other hydroxycinnamic acids, particularly caffeic acid, induces the synthesis of decarboxylase and reductase, stimulating the consumption of p-coumaric acid, which may be the precursor of some aroma compounds (Samaleh et al. 2008; Ye et al. 2014).

There were significant differences (p < 0.05) between the musts regarding the phloridzin content; the S2 sample was 58.64% higher than S1. Phloridzin is a flavonoid compound that is related to decreases in glycemia and the absorption of glucose. Therefore, high levels of this compound can be positive for human health, helping in weight loss and controlling hyperglycemia and Type 2 diabetes (Masumoto et al. 2009). Both samples showed a significant increase in phloridzin content during the fermentation process. According to Gosh et al. (2010), phloridzin can be formed from the bonding of glucose molecules to phloretin, through a reaction catalyzed by glycosyltransferases. The latter are enzymes that catalyze several glycosylated sterols with bioactive characteristics. These enzymes are naturally present in plants and can be codified by yeasts such as S. cerevisiae (Chen et al. 2018). Therefore, the phloridzin could have been synthesised during the fermentation process by the glycosylation of phloretin.

The S2 sample showed concentrations of six quercetin glycosides, which were inexistent or in low concentrations in the S1 sample. At the beginning of fermentation, there was an increase in the concentration of these flavonoids, which can be associated with the esterification effect of p-coumaric acid, as reported previously. The decrease in the concentration of some of these compounds during the process was possibly due to hydrolysis reactions catalyzed by β-glucosidase, an enzyme released by S. cerevisiae (Bimpilas et al. 2015).

Although there were significant differences between samples S1 and S2 for individual phenolic compounds, the evolution during the fermentative process followed the same trend for both samples. Thus, the addition of the extract did not compromise the reactions involving these compounds, which are important for the sensorial characteristics of cider.

As expected, the application of polyphenol-rich extract supplemented the beverage in terms of antioxidant capacity. At the end of fermentation, the S2 sample presented antioxidant activity 14 to 67% higher than the S1 sample in the CUPRAC and ABTS assays (Table 2). The quercetin glycosides showed the higher correlation coefficients with antioxidant activity in the samples, being the greatest effects were exerted by isoquercetin, reynoutrin and avicularin (rDPPH > 0.80; rABTS > 0.82; rFRAP > 0.89 and rCUPRAC > 0.58). These compounds presented the catechol group in B ring, the 2–3-double bond conjugated with the 4-oxo group on the heterocyclic ring, and two hydroxyls in the A ring, which favour antioxidant activity (Firuzi et al. 2005).

Colorimetric analysis

The colorimetric parameters of luminosity (L*), redness (a*), yellowness (b*), colour intensity (C*) and tonality (h°) showed significant differences (p < 0.05) between the S1 and S2 samples, indicating that phenolic compounds influenced the colour of the beverages (Table 3). In addition, there were variations during the fermentative process due to the changes in the composition of the beverage and the adsorption of some compounds by the yeast during the fermentative process (Alberti et al. 2016).

Table 3.

Parameters of the colorimetric analysis during fermentations days

Samples L* a* b* C h°
Apple must S1 83.05i ± 0.02 6.05b ± 0.04 61.18b ± 0.01 61.47b ± 0.04 84.35 h ± 0.01
S2 81.6j ± 0.2 6.8a ± 0.1 64.1a ± 0.3 64.4a ± 0.3 83.9i ± 0.1
Fermentation time (d) 1 S1 94.6f ± 0.1 − 4.51j ± 0.02 33.84d ± 0.06 34.14d ± 0.07 97.6a ± 0.1
S2 92.8 h ± 0.3 − 3.55i ± 0.09 38.6c ± 0.4 38.7c ± 0.4 95.3f ± 0.2
4 S1 95.7d ± 0.1 − 2.71 h ± 0.01 22.55f ± 0.04 22.71f ± 0.04 96.9b ± 0.1
S2 94.9 g ± 0.1 − 2.4 g ± 0.1 25.4e ± 0.1 25.5e ± 0.1 95e ± 6
7 S1 96.2b ± 0.2 − 2.12f ± 0.03 18.6i ± 0.5 18.7i ± 0.5 96.52c ± 0.06
S2 95.2e ± 0.2 − 2.11f ± 0.05 22.68f ± 0.01 22.8f ± 0.1 95ef ± 6
11 S1 96.57a ± 0.02 − 1.95e ± 0.01 17.9j ± 0.2 18.1j ± 0.2 96.2d ± 0.1
S2 95.8d ± 0.2 − 1.89d ± 0.01 20.9 g ± 0.1 21.0 g ± 0.2 95.g ± 6
15 S1 96.5a ± 0.1 − 1.83c ± 0.01 17 k ± 3 17.0 k ± 0.1 96.18d ± 0.06
S2 95c ± 4 − 1.82c ± 0.06 19.85 h ± 0.05 19.93 h ± 0.04 95f ± 5
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S1: sample without addition of the extract (control); S2: sample enhanced with phenolic extract; L*: luminosity; a*: chromaticity red/green; b*: chromaticity yellow/blue; C: Chrome–intensity; h°: hue angle–tonality; *: fermentations days

abcDifferent letters in the same column indicate significant difference between samples (p < 0.05)

Both the apple musts showed yellow tonality, with h° of approximately 90°. However, the S2 sample showed lower values for L*, and higher a*, b* and C* values than S1, which may have been related to the higher phenolic concentration. In addition, part of the phenolic compounds present in the apple pomace was oxidated due to the sequence of reactions catalysed by polyphenol oxidase (PPO), resulting in colourful compounds (Le Deun et al. 2015), which may have had a significant influence on the colour intensity of the S2 sample.

Sensorial analysis

As well in the instrumental analysis, the sensorial perception of colour intensity was higher in the S2 sample (Fig. 3). S2 also showed the highest values for bitterness and astringency, which is interesting since the combination of these attributes is related to the quality of cider (Los et al. 2017). In addition to procyanidins, other compounds, such as chlorogenic acid, phloridzin, and epicatechin are related to the perception of astringency (Lobo et al. 2018). Furthermore, according to Hufnagel and Hofmann (2008), quercetin glycosides, the main extracted compounds, are responsible for astringency in wines.

Fig. 3.

Fig. 3

Open in a new tab

The intensity of sensorial attributes perception (sourness, colour, bitterness and astringency) of the cider S1 (without the addition of extract) and S2 (with added extract) after 15 days of fermentation

The S1 sample showed a higher perception of sourness (Fig. 3), which is an attribute that is not influenced by phenolic composition (Symoneaux et al. 2014). Therefore, the difference in the perception of sourness between the samples was due to the higher perception of astringency and bitterness in the S2 sample, which masked the perception of sourness.

The t-test for odour quality showed that there was no significant difference between the samples (p > 0.05). Both the ciders presented mean scores that corresponded to the interval between “slightly liked” and “moderately liked”. Therefore, the phenolic concentration added through the extract did not harm the formation of aromas during the fermentation process.

Conclusion

This study presented for the first time the monitoring of cider composition during the fermentation with the application of polyphenol-rich extract recovered from apple pomace. The data appointed that the fermentation kinetics was not affected by the addition of extract. Also was verified that the cider with extract presented higher sugar content that resulted in a higher alcohol level. Among the monomeric phenols, quercetin glycosides and phloridzin was the main present in the extract. The monitoring of the phenolic profile during the fermentation showed the same trend in phenolic evolution in cider with and without extract. As a result of this approach about the cider quality, besides the expected increase in polyphenolic level and antioxidant activity, there was intensification in colour, bitterness, and astringency, without prejudices aroma quality.

Therefore, the evaluation of cider composition during the fermentation along with sensorial characteristics highlighted the industrial application potential of polyphenol-rich extract recovered from apple pomace as an alternative that valorizes apple pomace and improves the bioactive and technological quality of the cider. This sustainable and economically viable approach on a laboratory scale can facilitate design on a large scale, employing the concept of circular economy in agro-industries.

Acknowledgements

This study was financed, in part, by the Araucaria Foundation (FA, conv:009/2017; protocol: 16545) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior‐Brasil (CAPES)—Finance Code 001. A. Nogueira acknowledges the support of the National Council for Scientific and Technological Development (CNPq) (Grant #303789/2016-6).

Authors contributions

LB conceived, carried out the experiments and wrote; DGB, TEF and DMZ contributed with the experiments, analysis and writing of the manuscript; AN and AAFZ contributed with the data treatment and writing of the manuscript; AA supervised the work and edited the manuscript.

Footnotes

Publisher's Note

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References

  1. Alberti A, Zielinski AAF, Zardo DM, Demiate IM, Nogueira A, Mafra LI. Optimization of the extraction of phenolic compounds from apples using response surface methodology. Food Chem. 2014;149:151–158. doi: 10.1016/j.foodchem.2013.10.086. [DOI] [PubMed] [Google Scholar]
  2. Alberti A, Santos TPM, Zielinski AAF, Santos CME, Braga CM, Demiate IM, Nogueira A. Impact on chemical profile in apple juice and cider made from unripe, ripe and senescent dessert varieties. LWT Food Sci Technol. 2016;65:436–443. doi: 10.1016/j.lwt.2015.08.045. [DOI] [Google Scholar]
  3. Alberti A, Zielinski AAF, Couto M, Judacewski P, Mafra LI, Nogueira A. Distribution of phenolic compounds and antioxidant capacity in apple tissues during ripening. J Food Sci Technol. 2017;54:1511–1518. doi: 10.1007/s13197-017-2582-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Alonso-Salces RM, Herrero C, Barranco A, Barrueta LA, Gallo B, Francisca V. Technological classification of basque cider apple cultivars according to their polyphenolic profiles by pattern recognition analysis. J Agric Food Chem. 2004;52:8006–8016. doi: 10.1021/jf048995i. [DOI] [PubMed] [Google Scholar]
  5. AOAC-Association of Official Analytical Chemists (2016) Official methods of analysis of AOAC International. 20th edn. Gaithersburg
  6. Apak R, Özyürek M, Güçlü K, Çelik S. Mechanism of antioxidant capacity assays and the CUPRAC (cupric ion reducing antioxidant capacity assay) Microchim Acta. 2008;160:413–419. doi: 10.1007/s00604-007-0777-0. [DOI] [Google Scholar]
  7. Barreira JCM, Arraibi AA, Ferreira ICFR. Bioactive and functional compounds in apple pomace from juice and cider manufacturing: Potential use in dermal formulations. Trends Food Sci Tech. 2019;90:76–87. doi: 10.1016/j.tifs.2019.05.014. [DOI] [Google Scholar]
  8. Benzie IFF, Strain JJ. The ferric reducing ability of plasma (FRAP) as a measure of “antioxidant power”: the FRAP assay. Anal Biochem. 1996;239:70–76. doi: 10.1006/abio.1996.0292. [DOI] [PubMed] [Google Scholar]
  9. Bimpilas A, Tsimogiannis G, Balta-Brouma K, Lymperopoulou T, Oreopoulou V. Evolution of phenolic compounds and metal content of wine during alcoholic fermentation and storage. Food Chem. 2015;178:164–171. doi: 10.1016/j.foodchem.2015.01.090. [DOI] [PubMed] [Google Scholar]
  10. Bonneu M, Crouzet M, Urdaci M, Aigle M. Direct selection of yeast mutants with reduced viability on plates by erythrosine B. staining. Anal Biochem. 1991;19:225–230. doi: 10.1016/0003-2697(91)90013-J. [DOI] [PubMed] [Google Scholar]
  11. Brand-Williams W, Cuvelier ME, Berset C. Use of free radical method to evaluate antioxidant activity. LWT Food Sci Technol. 1995;22:25–30. doi: 10.1016/S0023-6438(95)80008-5. [DOI] [Google Scholar]
  12. Broadhurst RB, Jones WT. Analysis of condensed tannins using acidified vanillin. J Sci Food Agric. 1978;29:788–794. doi: 10.1002/jsfa.2740290908. [DOI] [Google Scholar]
  13. Chen L, Zhang Y, Feng Y. Structural dissection of sterol glycosyltransferase UGT51 from Saccharomyces cerevisiae for substrate specificity. J Struct Biol. 2018;204:371–379. doi: 10.1016/j.jsb.2018.11.001. [DOI] [PubMed] [Google Scholar]
  14. European Commission (2017). Report from the Commission to the European Parliament, the Council, the European economic and social committee and the committee of the regions on the implementation of the circular economy action plan. http://ec.europa.eu/environment/circular-economy/implementation_report.pdf. Accessed 01 Oct 2020.
  15. FAOSTAT (2020) Food and Agriculture Organization of the United Nations. Statistical Database. http://www.fao.org/faostat/en/#data/QC Accessed on 30 Sep 2020
  16. Fedor WS, Millar J, Accola JA. Sorbitol. Ind Eng Chem. 1960;52:282–286. doi: 10.1021/ie50604a018. [DOI] [Google Scholar]
  17. Firuzi O, Lacanna A, Petrucci R, Marrosu G, Saso L. Evaluation of the antioxidant activity of flavonoids by ferric reducing antioxidant power assay and cyclic voltammetry. Biochim Biophys Acta. 2005;1721:174–184. doi: 10.1016/j.bbagen.2004.11.001. [DOI] [PubMed] [Google Scholar]
  18. Gosh C, Halbwirth H, Stich K. Phloridzin: biosynthesis, distribution and physiological relevance in plants. Phytochemistry. 2010;71:838–843. doi: 10.1016/j.phytochem.2010.03.003. [DOI] [PubMed] [Google Scholar]
  19. González-García S, Argiz L, Míguez P, Gullón B. Exploring the production of bio-succinic acid from apple pomace using an environmental approach. Chem Eng J. 2018;350:982–991. doi: 10.1016/j.cej.2018.06.052. [DOI] [Google Scholar]
  20. Guo J, Yue T, Yuan Y. Impact of polyphenols on the headspace concentration of aroma compounds in apple cider. J Food Sci Technol. 2018;99:1635–1642. doi: 10.1002/jsfa.9345. [DOI] [PubMed] [Google Scholar]
  21. Hufnagel JC, Hofmann T. Orosensory-directed identification of astringent mouthfeel and bitter-tasting compounds in red wine. J Agric Food Chem. 2008;56:1376–1386. doi: 10.1021/jf073031n. [DOI] [PubMed] [Google Scholar]
  22. Le Bourvellec C, Guyot S, Renard CMGC. Interactions between apple (Malus domestica Borkh.) polyphenols and cell walls modulate the extractability of polysaccharides. Carbohydr Polym. 2009;75:251–261. doi: 10.1016/j.carbpol.2008.07.010. [DOI] [Google Scholar]
  23. Le Deun E, Van Der Welf R, Le Bail G, Lé Queré JM, Guyot S. HPLC-DAD-MS, Profiling of polyphenols responsible for yellow-orange color in apple juices of different French cider apple varieties. J Agric Food Chem. 2015;63:7675–7684. doi: 10.1021/acs.jafc.5b00988. [DOI] [PubMed] [Google Scholar]
  24. Lee B, Seo JD, Rhee JK, Kim CY. Heated apple juice supplemented with onion has greatly improved nutritional quality of and browning index. Food Chem. 2016;201:315–319. doi: 10.1016/j.foodchem.2016.01.092. [DOI] [PubMed] [Google Scholar]
  25. Lobo AP, Antón-Díaz MJ, Bedriñana RP, García OF, Hortal-Garcia R, Valles BS. Chemical, olfactometric and sensory description of single-variety cider apple juices obtained by crio-extraction. LWT Food Sci Technol. 2018;90:193–200. doi: 10.1016/j.lwt.2017.12.033. [DOI] [Google Scholar]
  26. Los PR, Braga CM, Carvalho JRF, Simões DRS, Nogueira A. Application of sensory analysis in the development of a new apple cider. Braz J Agroind Technol. 2017;10:2150–2168. doi: 10.3895/rbta.v11n1.3301. [DOI] [Google Scholar]
  27. Lu Z, Ye F, Zhou G, Gao R, Qin D, Zhao G. Micronized apple pomace as a novel emulsifier for food O/W Pickering emulsion. Food Chem. 2020;330:127325. doi: 10.1016/j.foodchem.2020.127325. [DOI] [PubMed] [Google Scholar]
  28. Madrera RR, Lobo AP, Valles BS. Phenolic profile on Asturian (Spain) natural cider. J Agric Food Chem. 2006;54:120–124. doi: 10.1021/jf051717e. [DOI] [PubMed] [Google Scholar]
  29. Madrera RR, Lobo AP, Alonso JJM. Effect of cider maturation on the chemical and sensory characteristics in fresh cider spirits. Food Res Int. 2010;43:70–78. doi: 10.1016/j.foodres.2009.08.014. [DOI] [Google Scholar]
  30. Masumoto S, Akimoto Y, Oike H, Kobori M. Dietary phloridzin reduces blood glucose levels and reverses Sglt1 expression in the small intestine in Streptozotocin-induced diabetic mice. J Agric Food Chem. 2009;57:4651–1656. doi: 10.1021/jf9008197. [DOI] [PubMed] [Google Scholar]
  31. Popa C. Ethylene measurements from sweet fruits flowers using photoacoustic spectroscopy. Molecules. 2019;24:1144. doi: 10.3390/molecules24061144. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Re R, Pellegrini N, Protegentte A, Pannala A, Yang M, Rice-Evans C. Antioxidant activity applying an improved ABST radical cation decolorization assay. Free Radic Biol Med. 1999;26:12311–21237. doi: 10.1016/s0891-5849(98)00315-3. [DOI] [PubMed] [Google Scholar]
  33. Renard CMGC. Extraction of bioactives from fruit and vegetables: state of the art and perspectives. LWT Food Sci Technol. 2018;93:390–395. doi: 10.1016/j.lwt.2018.03.063. [DOI] [Google Scholar]
  34. Samaleh D, Brandam C, Medawar W, Lteif R, Strehaiano P. Highlight on the problems generated by p-coumaric acid analysis in wine fermentations. Food Chem. 2008;107:1661–1667. doi: 10.1016/j.foodchem.2007.09.052. [DOI] [Google Scholar]
  35. Santos TPM, Alberti A, Judacewski P, Zielinski AA, Nogueira A. Effect of sulphur dioxide concentration added at different processing stages on volatile composition of ciders. J Inst Brew. 2018;124:261–268. doi: 10.1002/jib.500. [DOI] [Google Scholar]
  36. Singleton VL, Rossi JA. Colorimetry of total phenolic with phosphomolybdic-phosphotungstic acid reagent. J Enol Vitic. 1965;16:144–158. [Google Scholar]
  37. Suaréz B, Álvarez AL, García YD, Del Barrio G, Lobo AP, Parra F. Phenolic profiles, antioxidant activity and in vitro antiviral properties of apple pomace. Food Chem. 2010;120:339–342. doi: 10.1016/j.foodchem.2009.09.073. [DOI] [Google Scholar]
  38. Symoneaux R, Baron A, Marnet N, Bauduin R, Chollet S. Impact of apple procyanidins on sensory perception in model cider (part 1): polymerisation degree and concentration. LWT Food Sci Technol. 2014;57:22–27. doi: 10.1016/j.lwt.2013.11.016. [DOI] [Google Scholar]
  39. Van Der Sluis AA, Dekker M, Skrede G, Jongen WMF. Activity and concentration of polyphenolic antioxidants in apple juice. 1. Effect of existing production methods. J Agric Food Chem. 2002;50:7211–7219. doi: 10.1021/jf020115h. [DOI] [PubMed] [Google Scholar]
  40. Ye M, Yue T, Yuan Y. Evolution of polyphenols and organic acids during the fermentation of apple cider. J Sci Food Agric. 2014;94:2951–2957. doi: 10.1002/jsfa.6639. [DOI] [PubMed] [Google Scholar]
  41. Zardo DM, Silva KM, Guyot S, Nogueira A. Phenolic profile and antioxidant capacity of the principal apples produced in Brazil. Int J Food Sci Nutr. 2013;6:727–735. doi: 10.3109/09637486.2013.763909. [DOI] [PubMed] [Google Scholar]
  42. Zhishen J, Mengcheng T, Jianming W. The determination of flavonoid contents in mulberry and their scavenging effects on superoxide radicals. Food Chem. 1999;64:555–559. doi: 10.1016/S0308-8146(98)00102-2. [DOI] [Google Scholar]
  43. Zielinski AAF, Braga CM, Demiate IM, Beltrame FL, Nogueira A, Wosiacki G. Development and optimization of a HPLC-RI method for the determination of major sugars in apple juice and evaluation of the effect of the ripening stage. LWT Food Sci Technol. 2014;34:38–43. doi: 10.1590/S0101-20612014005000003. [DOI] [Google Scholar]

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