Apple By-Product Valorisation: History
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Contributor:
Rocío De la Peña-Armada
,
Inmaculada Mateos-Aparicio

About 30% of the total production of apples is processed, being juice and cider the main resulting products. Regarding this procedure, a large quantity of apple by-product is generated, which tends to be undervalued, and commonly remains underutilised, landfilled, or incinerated. However, apple by-product is a proven source of bioactive compounds, namely dietary fibre, fatty acids, triterpenes, or polyphenols. Therefore, the application of green technologies should be considered in order to improve the functionality of apple by-product while promoting its use as the raw material of a novel product line. 

  • apple
  • apple by-product
  • valorisation
  • green technologies
  • bioactive compounds

1. Apple By-Product

Apple by-product could be defined as the remaining solid of apple processing in order to obtain juices or cider, among other products. It is mainly constituted of apple peel, seeds, stems, and pulp. Regarding the proximate composition of apple by-product (Table 1), the main element, overall, is dietary fibre, followed by non-fibrous carbohydrates, lipids, proteins, and ashes. Apple by-product has been recognised as a health-promoting ingredient by numerous authors (Table 2) and due to its composition, it has been determined as a potential source of bioactive compounds, such as dietary fibre, and also phenolic compounds, triterpenoids, or fatty acids (Figure 1) [1][2][3]. Polyphenolic antioxidants in apples are predominantly located in the skin, thus, most polyphenols persist in the apple pomace [2]. Phenolic compounds found in apple by-product include flavanols as the major class of apple polyphenols, followed by hydroxycinnamic acid derivatives, flavonols, di-hydrochalcones, and anthocyanins [1]. They have exhibited a high scavenging activity, indicating apple by-product as a potential source of dietary antioxidants [4]. Besides, triterpenic acids are abundant in many plants, including apples [5]. Particularly, apple terpenoids might be found either in the peel epidermal cells or epicuticular wax, which are often discarded as food processing industry waste [6][7]. Triterpenic acids have demonstrated various pharmacological properties and health effects, such as antioxidant, anti-inflammatory, or antimicrobial effects, increasing the attraction to producing healthcare products with multifunctional values [5][8]. Regarding fatty acids, recent studies have verified the presence of unsaturated fatty acids in the apple seed and apple peel. Particularly, oleic, linoleic, and linolenic acids have been described as the main components of this lipid fraction [3][9]. The contribution of the fatty acids to the potential antioxidant, antimicrobial, and antiproliferative capacities of apple seed oil has been proved [10][11][12].
Figure 1. Apple by-product as a source of terpenoids, phenolic compounds, fatty acids, and dietary fibre.
Table 1. Proximate composition of apple pomace in dry matter (%).
TDF SDF IDF Non-Fibrous Carbohydrates Protein Lipids Ashes Reference
55.48 ± 0.7 11.06 ± 0.1 43.58 ± 0.6 28.48 ± 1.1 6.25 ± 0.1 6.58 ± 0.1 1.56 ± 0.3 [13]
- - - - 3.8 ± 0.13 1.2 ± 0.10 1.5 ± 0.02 [14]
- 20.63 ± 2.00 62.08 ± 0.77 - 4.36 ± 0.24 7.36 ± 0.74 - [15]
64.84  ±  1.78 20.27  ±  0.09 44.57  ±  0.24 - 3.57  ±  0.08 - 4.29  ±  0.06 [16]
53.1 ± 0.7 6.1 ± 0.2 47.0 ± 0.8 - 0.5 ± 0.0 - 1.8 ± 0.0 [17]
76.84 ± 1.24 18.97 ± 0.92 57.87 ± 0.33 6.72 ± 1.54 6.98 ± 0.32 8.19 ± 0.05 1.26 ± 0.12 [18]
60.48 - - - 2.28 3.84 6.67 [19]
8.86 ± 0.50     74.44 ± 0.15 3.42 ± 0.94 0.26 ± 0.13 1.68 ± 0.74 [20]
51.10 ± 1.86 14.60 ± 0.14 36.50 ± 1.14 - 2.06 ± 0.05 2.70 ± 0.10 0.50 ± 0.05 [21]
78.2 ± 0.60 14.33 ± 0.61 63.9 ± 0.16 13.3 3.12 ± 0.07 1.57 ± 0.08 1.88 ± 0.11 [22]
TDF: total dietary fibre; SDF: soluble dietary fibre; IDF: insoluble dietary fibre.
Table 2. Revision of the studies of the effects of the apple by-product on health.
Study Characteristics Results References
Female Sprague–Dawley rats randomly assigned: standard purified rodent diet or AIN-93G, AIN-93G with freeze-dried apple pomace, or Western diet, or Western diet with freeze-dried apple pomace. Improved liver and adipose inflammatory and antioxidant status:
Rats consuming Western/AP downregulated hepatic and adipose proinflammatory cytokine gene expression and improved antioxidant status compared to rats consuming a Western diet.		 [23]
In vitro digested apple pomace and pectin fractions derived from three apple varieties were subjected to faecal batch fermentation by using samples from healthy donors and from patients of Crohn’s disease. Prebiotic potential:
Growth of Akkermansia, Lachnospiraceae UCG-010, Prevotella, Sucinivibrio, and Turicibacter on samples from healthy donors, whereas Blautia, Lachnospiraceae CAG-56, Dialister, Eubacterium eligens, and Intestinimonas were stimulated in fermentations from inflammatory bowel disease patients.		 [24]
Male C57BL/6J mice were exposed to a high-fat and sucrose diet without and with the addition of 10 mg apple pomace flower per day whereas the control groups were fed with standard pellet rodent diet without. Antioxidant, antidiabetic, and antiobesity effects:
Long-term supplementation with apple pomace flower was shown to decrease glycemia, significantly improve glucose tolerance, and decrease body weight gain in mice exposed to a high-fat and sucrose diet.		 [25]
Wistar Hannover rats were fed with high-fat diets for 5 weeks and randomised in two groups (control and supplemented with apple by-product). Diets were prepared from a commercial diet AIN-210 enriched with fat. Prebiotic and hypolipidemic effect:
Butyrate was increased 3-fold in this in vivo assay indicating that butyrate bacteria producers can use apple by-product.
Apple by-product enriched diet increased HDL and diminished trygliceridemia and hepatic total lipids.		 [13]
Male F344 rats were fed a control feed or the same feed with 2.1%, or 6.5% dry apple pomace, with or without seeds for 4 weeks. Hypocholesterolemic effect and improved gut health:
Pomace feeding decreased total-, LDL- and IDL-cholesterol concentrations, increased production of SCFA and increased excretion of total- and primary bile acids. No hepatotoxic or other effects were derived from apple seeds.		 [26]
Male Sprague–Dawley rats were assigned to four groups: the normal diet group, the high-fat diet group, and high-fat diet group containing either apple pomace or apple juice concentrate. Loss of body weight and fat and improved lipid profiles:
Body weight gain, white adipose tissue, weight, serum total cholesterol, LDL cholesterol, and triglyceride concentrations, epididymal adipocyte size, and lesion scores were significantly lower and serum HDL cholesterol concentration and brown adipose tissue weights were significantly higher in the apple pomace and apple juice concentrate groups compared with the high-fat diet group.		 [27]
Dietary fibre represents the highest contribution in the proximate composition of apple by-product (55.48 ± 0.7 g/100 g dry matter). Insoluble dietary fibre (IDF) accounts for the greatest proportion (43.58 ± 0.6 g/100 g dry matter) whereas soluble dietary fibre (SDF), represents a lower percentage (11.06 ± 0.1 g/100 g dry matter) [13]. Besides, apple by-product’ dietary fibre is mainly constituted of non-starch polysaccharides, including a high range of molecular sizes, structures, and monomeric composition. De la Peña-Armada and collaborators [28] determined the configuration of the total dietary fibre indicating uronic acids and glucose as principal components. In addition, arabinose, xylose, and galactose were also remarkable, suggesting the presence of pectin substances made of arabinans, arabinoxylans, homogalacturonans, arabinogalactans, or galactans as side chains.
Pectins are present in the cell walls and intracellular tissues of fruit and vegetables [29]. They are mainly composed of numerous chains of galacturonic acid and are characterised by being resistant to human digestive enzymes. Pectins can be fermented along the intestine favouring the growth of Lactobacillus or Bifidobacteria, therefore promoting the release of acetate and propionate, and enhancing gut health [30][31]. In fact, apple by-product potential as a prebiotic ingredient has been demonstrated and mainly attributed to its pectin content [13][30][32][33].
Gibson and collaborators [34] proposed the following definition of a prebiotic: “A substrate that is selectively utilised by host microorganisms conferring a health benefit.” Certain fermentable carbohydrates have been described to promote a prebiotic effect. However, the most widely documented dietary prebiotics are the non-digestible oligosaccharides fructans and galactans [35]. Prebiotics have the potential to improve digestive function, modulate the immune system, improve mineral absorption, or help glucose metabolism. Furthermore, prebiotic compounds can promote metabolic health, including preventing insulin resistance and promoting healthy blood lipid levels [36][37]. The main derived products of bacterial prebiotic metabolism are the short-chain fatty acids, namely, acetate, butyrate, and propionate. These compounds are known to interact with the host systems, leading to health benefits in the gut microbial community and consequently elsewhere in the body. Thus, short-chain fatty acids have been suggested as an interesting strategy for gastrointestinal dysfunction, obesity, and type 2 diabetes mellitus prevention [38]. Besides, the feasibility of recovering prebiotic substrates from novel sources, such as food by-product, has been recently proposed for addressing the economic and environmental current needs [39].
Therefore, efforts of the juice and cider industry should be focused on the valorisation of the apple by-product for the development of functional foods, dietary supplements, and/or food additives [33].

2. Valorisation Procedures

Sustainable chemistry has suggested that food by-products are rich sources of bioactive compounds [40]. The convenience of improving this raw material’s functionality, namely, increasing the accessibility to the health-promoting components, suggests the possibility to design different transformation strategies. The enhancement of the nutritional value of by-products is of great relevance due to its human health, economic, and environmental benefits [41]. In this regard, green processes are based on methodologies with low energy consumption, use Generally Recognised as Safe (GRAS) solvents, and ensure a high-quality and safe product [42]. The main objective of those procedures consists of developing new natural resource products with added value while decreasing waste generation. Emerging technologies, such as ultrasound, enzyme digestion, or pulsed electric field, have been developed over the last fifty years. However, these innovative alternatives have been greatly implemented in the food, pharmaceutical, and cosmetic sectors [42][43]. Indeed, numerous studies are focused on the application of microwave, ultrasound, enzymes, high hydrostatic pressure, and supercritical fluid extraction, among others, for food by-product valorisation (Figure 2) [43].
Molecules 27 06937 g004 550
Figure 2. Apple industry based on green and sustainable technologies in the scope of circular economy.
Microwave extraction has developed an important role in food science and technology over the last two decades. Microwaves generate heat after their contact with cellular polar compounds. The heat disrupts the cell walls and therefore enhances the availability of certain components [44]. Microwave-assisted extractions are generally performed in polar media such as water, acetone, alcohol, or mixtures. The reaction typically requires between seconds and a few minutes [45]. Furthermore, microwaves have been studied in combination with different processing technologies. In fact, the microwave-assisted ultrasound extraction technique has been described as a novel method for fast and efficient extraction. It has great potential for commercial applications due to the fast sample preparation and the appropriate balance between costs and effectiveness [46]. On the other hand, ultrasound is based on sound waves, i.e., mechanical vibrations, which, when applied to plant-based matrices, can collapse cavitation bubbles close to cell walls, producing a cell disruption. Thus, this methodology enhances the extraction processes [44]. The spectrum of ultrasonic wave frequency varies in the range from 20 kHz, considered the audible range, up to 10 MHz [47].
Enzyme-assisted extraction methods are becoming increasingly popular [48]. Enzymes, which can be found in nature, have been used for thousands of years to produce different food products. However, the latest development within biotechnology enables the creation of tailor-made enzymes, which display new activities, and can be adapted to diverse process conditions [49]. This enzymatic non-conventional methodology provides the opportunity of processing foods in a short time and at a low temperature, achieving high extraction yield in the industry [50]. The substrate specificity favours the extraction of a great number of bioactive compounds from the food matrix [48]. Therefore, according to the desired results after the application of this methodology, the enzyme utilised for the procedure will vary. For instance, if the main goal is cell wall disruption, degradation is generally carried out by complex cellulolytic enzyme preparations, which contain a mixture of several cellulase kinds [51]. Thus, inaccessible bound forms, contained within cellular walls, can be released and their availability increased [48]. Enzyme-assisted extraction is usually considered within the so-called bioprocessing. Bioprocessing includes numerous methodologies in which microbial fermentation is notable. Fermentation requires the contribution of living microorganisms for the generation of new products. In addition, improves organoleptic properties, increases the product shelf-life and modifies the nutritional profile of food. The fermentation valorisation process has been demonstrated to be a feasible method to improve bioactive component content in food by-products [52][53][54][55][56].
High hydrostatic pressure (HHP) treatment is a cold pasteurisation technique in which products are subjected to a high level of isostatic pressure transmitted by water. The application of this technology destroys pathogens, extends product shelf-life and only requires water and electricity. Furthermore, numerous studies have concluded that HHP is not only a conservation technology but also enables the extraction of bioactive compounds [45][57]. HHP may increase the extractability of phenols, carotenoids, and anthocyanins, and also the bioavailability of minerals, antioxidants, and starch [45]. Besides, HHP could be relevant for food by-product valorisation, since these derived products have been over-processed, and further treatments, especially thermal procedures, could cause an excessive loss of their bioactive compounds’ functionality [58]. Additionally, HHP has been combined with different methodologies, including the incorporation of food-grade enzymes into the process for a potential application in the enhancement of the health benefits of food products [57][59]. Particularly, HHP assisted by certain enzymes has resulted in an increase in the enzymatic activity that may be due to a change in the active site or in substrate specificity [60].
Another alternative green process for food by-product valorisation is supercritical fluid extraction (SFE). The supercritical technique has been used since 1882 and its main application fields are food and flavour, pharmaceuticals, and various biochemical sectors [61]. Supercritical carbon dioxide enables a clean extraction to separate different components from food matrices, producing a pure and safe product [62][63]. Particularly, CO2 is a non-polar solvent which facilitates lipophilic compound obtention [10][64]. In addition, this procedure has other major advantages, such as the low critical temperature required for it to be conducted, or the absence of light and air during the process, which reduces the risk of recovered compound degradation [65].
Emerging technologies present various applications forms, including small-scale and large-scale, entailing industrial uses, such as food or nutraceutical processing [48]. Hence, in order to reintroduce the apple by-product back into the food chain, these technologies represent an interesting option for the present and future time.

This entry is adapted from the peer-reviewed paper 10.3390/molecules27206937

References

  1. Barreira, J.C.M.; Arraibi, A.A.; Ferreira, I.C.F.R. Bioactive and Functional Compounds in Apple Pomace from Juice and Cider Manufacturing: Potential Use in Dermal Formulations. Trends Food Sci. Technol. 2019, 90, 76–87.
  2. Skinner, R.C.; Gigliotti, J.C.; Ku, K.M.; Tou, J.C. A Comprehensive Analysis of the Composition, Health Benefits, and Safety of Apple Pomace. Nutr. Rev. 2018, 76, 893–909.
  3. De la Peña Armada, R.; Bronze, M.R.; Matias, A.; Mateos-Aparicio, I. Triterpene-Rich Supercritical CO2 Extracts from Apple By-Product Protect Human Keratinocytes Against ROS. Food Bioproc. Tech. 2021, 14, 909–919.
  4. Li, W.; Yang, R.; Ying, D.; Yu, J.; Sanguansri, L.; Augustin, M.A. Analysis of Polyphenols in Apple Pomace: A Comparative Study of Different Extraction and Hydrolysis Procedures. Ind. Crops Prod. 2020, 147, 112250.
  5. Nile, S.H.; Nile, A.; Liu, J.; Kim, D.H.; Kai, G. Exploitation of Apple Pomace towards Extraction of Triterpenic Acids, Antioxidant Potential, Cytotoxic Effects, and Inhibition of Clinically Important Enzymes. Food Chem. Toxicol. 2019, 131, 110563.
  6. Poirier, B.C.; Buchanan, D.A.; Rudell, D.R.; Mattheis, J.P. Differential Partitioning of Triterpenes and Triterpene Esters in Apple Peel. J. Agric. Food Chem. 2018, 66, 1800–1806.
  7. Szakiel, A.; Pączkowski, C.; Pensec, F.; Bertsch, C. Fruit Cuticular Waxes as a Source of Biologically Active Triterpenoids. Phytochem. Rev. 2012, 11, 263–284.
  8. Grigoras, C.G.; Destandau, E.; Fougère, L.; Elfakir, C. Evaluation of Apple Pomace Extracts as a Source of Bioactive Compounds. Ind. Crops Prod. 2013, 49, 794–804.
  9. Klein, B.; Thewes, F.R.; Rogério de Oliveira, A.; Brackmann, A.; Barin, J.S.; Cichoski, A.J.; Wagner, R. Development of Dispersive Solvent Extraction Method to Determine the Chemical Composition of Apple Peel Wax. Food Res. Int. 2019, 116, 611–619.
  10. Montañés, F.; Catchpole, O.J.; Tallon, S.; Mitchell, K.A.; Scott, D.; Webby, R.F. Extraction of Apple Seed Oil by Supercritical Carbon Dioxide at Pressures up to 1300 bar. J. Supercrit. Fluids 2018, 141, 128–136.
  11. Walia, M.; Rawat, K.; Bhushan, S.; Padwad, Y.S.; Singh, B. Fatty Acid Composition, Physicochemical Properties, Antioxidant and Cytotoxic Activity of Apple Seed Oil Obtained from Apple Pomace. J. Sci. Food Agric. 2014, 94, 929–934.
  12. Tian, H.L.; Zhan, P.; Li, K.X. Analysis of Components and Study on Antioxidant and Antimicrobial Activities of Oil in Apple Seeds. Int. J. Food Sci. Nutr. 2010, 61, 395–403.
  13. Mateos-Aparicio, I.; de la Peña Armada, R.; Pérez-Cózar, M.L.; Rupérez, P.; Redondo-Cuenca, A.; Villanueva-Suárez, M.J. Apple By-Product Dietary Fibre Exhibits Potential Prebiotic and Hypolipidemic Effectsin High-Fat Fed Wistar Rats. Bioact. Carbohydr. Diet. Fibre 2020, 23, 100219.
  14. Davies, S.J.; Guroy, D.; Hassaan, M.S.; El-Ajnaf, S.M.; El-Haroun, E. Evaluation of Co-Fermented Apple-Pomace, Molasses and Formic Acid Generated Sardine Based Fish Silages as Fishmeal Substitutes in Diets for Juvenile European Sea Bass (Dicentrachus Labrax) Production. Aquaculture 2020, 521, 735087.
  15. 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.
  16. Kırbaş, Z.; Kumcuoglu, S.; Tavman, S. Effects of Apple, Orange and Carrot Pomace Powders on Gluten-Free Batter Rheology and Cake Properties. J. Food Sci. Technol. 2019, 56, 914–926.
  17. Wang, S.; Gu, B.J.; Ganjyal, G.M. Impacts of the Inclusion of Various Fruit Pomace Types on the Expansion of Corn Starch Extrudates. LWT 2019, 110, 223–230.
  18. Macagnan, F.T.; dos Santos, L.R.; Roberto, B.S.; de Moura, F.A.; Bizzani, M.; da Silva, L.P. Biological Properties of Apple Pomace, Orange Bagasse and Passion Fruit Peel as Alternative Sources of Dietary Fibre. Bioact. Carbohydr. Diet. Fibre 2015, 6, 1–6.
  19. Choi, Y.S.; Kim, Y.B.; Hwang, K.E.; Song, D.H.; Ham, Y.K.; Kim, H.W.; Sung, J.M.; Kim, C.J. Effect of Apple Pomace Fiber and Pork Fat Levels on Quality Characteristics of Uncured, Reduced-Fat Chicken Sausages. Poult. Sci. 2016, 95, 1465–1471.
  20. Leyva-Corral, J.; Quintero-Ramos, A.; Camacho-Dávila, A.; de Jesús Zazueta-Morales, J.; Aguilar-Palazuelos, E.; Ruiz-Gutiérrez, M.G.; Meléndez-Pizarro, C.O.; de Jesús Ruiz-Anchondo, T. Polyphenolic Compound Stability and Antioxidant Capacity of Apple Pomace in an Extruded Cereal. LWT—Food Sci. Technol. 2016, 65, 228–236.
  21. Sudha, M.L.; Baskaran, V.; Leelavathi, K. Apple Pomace as a Source of Dietary Fiber and Polyphenols and Its Effect on the Rheological Characteristics and Cake Making. Food Chem. 2007, 104, 686–692.
  22. Figuerola, F.; Hurtado, M.L.; Estévez, A.M.; Chiffelle, I.; Asenjo, F. Fibre Concentrates from Apple Pomace and Citrus Peel as Potential Fibre Sources for Food Enrichment. Food Chem. 2005, 91, 395–401.
  23. Skinner, R.C.; Warren, D.C.; Naveed, M.; Agarwal, G.; Benedito, V.A.; Tou, J.C. Apple Pomace Improves Liver and Adipose Inflammatory and Antioxidant Status in Young Female Rats Consuming a Western Diet. J. Funct. Foods 2019, 61, 103471.
  24. Calvete-Torre, I.; Sabater, C.; Antón, M.J.; Moreno, F.J.; Riestra, S.; Margolles, A.; Ruiz, L. Prebiotic Potential of Apple Pomace and Pectins from Different Apple Varieties: Modulatory Effects on Key Target Commensal Microbial Populations. Food Hydrocoll. 2022, 133, 107958.
  25. Gorjanović, S.; Micić, D.; Pastor, F.; Tosti, T.; Kalušević, A.; Ristić, S.; Zlatanovic, S. Evaluation of Apple Pomace Flour Obtained Industrially by Dehydration as a Source of Biomolecules with Antioxidant, Antidiabetic and Antiobesity Effects. Antioxidants 2020, 9, 413.
  26. Ravn-Haren, G.; Krath, B.N.; Markowski, J.; Poulsen, M.; Hansen, M.; Kołodziejczyk, K.; Kosmala, M.; Dragsted, L.O. Apple Pomace Improves Gut Health in Fisher Rats Independent of Seed Content. Food Funct. 2018, 9, 2931–2941.
  27. Cho, K.D.; Han, C.K.; Lee, B.H. Loss of Body Weight and Fat and Improved Lipid Profiles in Obese Rats Fed Apple Pomace or Apple Juice Concentrate. J. Med. Food 2013, 16, 823–830.
  28. De la Peña-Armada, R.; Villanueva, A.M.J.; Mateos, S.I. High Hydrostatic Pressure Processing Enhances Pectin Solubilisation on Apple by—Product Improving Techno—Functional Properties. Eur. Food Res. Technol. 2020, 146, 111421.
  29. Gray, J. Dietary Fibre Definition, Analysis, Physiology Health; Champ, M., Ed.; ILSI Europe: Brussels, Belgium, 2006.
  30. Singh, R.P.; Tingirikari, J.M.R. Agro Waste Derived Pectin Poly and Oligosaccharides: Synthesis and Functional Characterization. Biocatal. Agric. Biotechnol. 2021, 31, 101910.
  31. Ribeiro, J.A.; dos Santos Pereira, E.; de Oliveira Raphaelli, C.; Radünz, M.; Camargo, T.M.; da Rocha Concenço, F.I.G.; Cantillano, R.F.F.; Fiorentini, Â.M.; Nora, L. Application of Prebiotics in Apple Products and Potential Health Benefits. J. Food Sci. Technol. 2022, 59, 1249–1262.
  32. Mateos-Aparicio, I. Food Waste Recovery. Processing Technologies, Industrial Techniques, and Applications. In Plant-based by-products; Galanakis, C.M., Ed.; Academic Press: Cambridge, MA, USA, 2020; pp. 367–397.
  33. De la Peña-Armada, R.; Villanueva-Suárez, M.J.; Molina-García, A.D.; Rupérez, P.; Mateos-Aparicio, I. Novel Rich-in-Soluble Dietary Fiber Apple Ingredient Obtained from the Synergistic Effect of High Hydrostatic Pressure Aided by Celluclast®. LWT 2021, 146, 111421.
  34. Gibson, G.R.; Hutkins, R.; Sanders, M.E.; Prescott, S.L.; Reimer, R.A.; Salminen, S.J.; Scott, K.; Stanton, C.; Swanson, K.S.; Cani, P.D.; et al. Expert Consensus Document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) Consensus Statement on the Definition and Scope of Prebiotics. Nat. Rev. Gastroenterol. Hepatol. 2017, 14, 491–502.
  35. Rastall, R.A.; Gibson, G.R. Recent Developments in Prebiotics to Selectively Impact Beneficial Microbes and Promote Intestinal Health. Curr. Opin. Biotechnol. 2015, 32, 42–46.
  36. Roberfroid, M.; Gibson, G.R.; Hoyles, L.; McCartney, A.L.; Rastall, R.; Rowland, I.; Wolvers, D.; Watzl, B.; Szajewska, H.; Stahl, B. Prebiotic Effects: Metabolic and Health Benefits. Br. J. Nutr. 2010, 104, S1–S63.
  37. Włodarczyk, M.; Śliżewska, K. Obesity as the 21st Century’s Major Disease: The Role of Probiotics and Prebiotics in Prevention and Treatment. Food Biosci. 2021, 42, 101115.
  38. Blaak, E.E.; Canfora, E.E.; Theis, S.; Frost, G.; Groen, A.K.; Mithieux, G.; Nauta, A.; Scott, K.; Stahl, B.; van Harsselaar, J.; et al. Short Chain Fatty Acids in Human Gut and Metabolic Health. Benef. Microbes 2020, 11, 411–455.
  39. Cunningham, M.; Azcarate-Peril, M.A.; Barnard, A.; Benoit, V.; Grimaldi, R.; Guyonnet, D.; Holscher, H.D.; Hunter, K.; Manurung, S.; Obis, D.; et al. Shaping the Future of Probiotics and Prebiotics. Trends Microbiol. 2021, 29, 667–685.
  40. Gómez-García, R.; Campos, D.A.; Aguilar, C.N.; Madureira, A.R.; Pintado, M. Valorisation of Food Agro-Industrial by-Products: From the Past to the Present and Perspectives. J. Environ. Manag. 2021, 299, 113571.
  41. Iqbal, A.; Schulz, P.; Rizvi, S.S.H. Valorization of Bioactive Compounds in Fruit Pomace from Agro-Fruit Industries: Present Insights and Future Challenges. Food Biosci. 2021, 44, 101384.
  42. Chemat, F.; Abert-Vian, M.; Fabiano-Tixier, A.S.; Strube, J.; Uhlenbrock, L.; Gunjevic, V.; Cravotto, G. Green Extraction of Natural Products. Origins, Current Status, and Future Challenges. TrAC—Trends Anal. Chem. 2019, 118, 248–263.
  43. Mateos-Aparicio, I.; Matias, A. Food Industry Processing By-Products in Foods; Elsevier Inc.: Amsterdam, The Netherlands, 2019.
  44. Marić, M.; Nin, A.; Zhu, Z.; Barba, F.J.; Brn, M.; Rimac, S. An Overview of the Traditional and Innovative Approaches for Pectin Extraction from Plant Food Wastes and By-Products: Ultrasound-, Microwaves-, and Enzyme-Assisted Extraction. Trends Food Sci. Technol. 2018, 76, 28–37.
  45. Arshadi, M.; Attard, T.M.; Lukasik, R.M.; Brncic, M.; da Costa Lopes, A.M.; Finell, M.; Geladi, P.; Gerschenson, L.N.; Gogus, F.; Herrero, M.; et al. Pre-Treatment and Extraction Techniques for Recovery of Added Value Compounds from Wastes throughout the Agri-Food Chain. Green Chem. 2016, 18, 6160–6204.
  46. Chizoba Ekezie, F.G.; Sun, D.W.; Han, Z.; Cheng, J.H. Microwave-Assisted Food Processing Technologies for Enhancing Product Quality and Process Efficiency: A Review of Recent Developments. Trends Food Sci. Technol. 2017, 67, 58–69.
  47. Singla, M.; Sit, N. Application of Ultrasound in Combination with Other Technologies in Food Processing: A Review. Ultrason. Sonochem. 2021, 73, 105506.
  48. Gligor, O.; Mocan, A.; Moldovan, C.; Locatelli, M.; Crișan, G.; Ferreira, I.C.F.R. Enzyme-Assisted Extractions of Polyphenols—A Comprehensive Review. Trends Food Sci. Technol. 2019, 88, 302–315.
  49. Kirk, O.; Borchert, T.V.; Fuglsang, C.C. Industrial Enzyme Applications. Curr. Opin. Biotechnol. 2002, 13, 345–351.
  50. Roselló-Soto, E.; Parniakov, O.; Deng, Q.; Patras, A.; Koubaa, M.; Grimi, N.; Boussetta, N.; Tiwari, B.K.; Vorobiev, E.; Lebovka, N.; et al. Application of Non-Conventional Extraction Methods: Toward a Sustainable and Green Production of Valuable Compounds from Mushrooms. Food Eng. Rev. 2016, 8, 214–234.
  51. Bélafi-Bakó, K. Enzymatic Extraction and Fermentation for the Recovery of Food Processing Products; Woodhead Publishing Limited: Sawston, UK, 2007; Volume 1.
  52. Rodríguez Madrera, R.; Pando Bedriñana, R.; Suárez Valles, B. Enhancement of the Nutritional Properties of Apple Pomace by Fermentation with Autochthonous Yeasts. LWT—Food Sci. Technol. 2017, 79, 27–33.
  53. Yadav, M.; Ahmadi, Y.; Chiu, F.-C. Handbook of Polymer Nanocomposites for Industrial Applications. In Food and Bioprocessing Industry; Mustansar Hussain, C., Ed.; Elsevier: Amsterdam, The Netherlands, 2021.
  54. Leonard, W.; Zhang, P.; Ying, D.; Adhikari, B.; Fang, Z. Fermentation Transforms the Phenolic Profiles and Bioactivities of Plant-Based Foods. Biotechnol. Adv. 2021, 49, 107763.
  55. Zhang, F.; Wang, T.; Wang, X.; Lü, X. Apple Pomace as a Potential Valuable Resource for Full-Components Utilization: A Review. J. Clean. Prod. 2021, 329, 129676.
  56. Leonel, L.V.; Sene, L.; da Cunha, M.A.A.; Dalanhol, K.C.F.; de Almeida Felipe, M.d.G. Valorization of Apple Pomace Using Bio-Based Technology for the Production of Xylitol and 2G Ethanol. Bioprocess Biosyst. Eng. 2020, 43, 2153–2163.
  57. Huang, J.; Liao, J.; Qi, J.; Jiang, W.; Yang, X. Structural and Physicochemical Properties of Pectin-Rich Dietary Fiber Prepared from Citrus Peel. Food Hydrocoll. 2021, 110, 106140.
  58. Galanakis, C.M. Emerging Technologies for the Production of Nutraceuticals from Agricultural By-Products: A Viewpoint of Opportunities and Challenges. Food Bioprod. Process. 2013, 91, 575–579.
  59. Tsevdou, M.; Gogou, E.; Taoukis, P. High Hydrostatic Pressure Processing of Foods; Elsevier Inc.: Amsterdam, The Netherlands, 2019.
  60. Pérez-lópez, E.; Mateos-aparicio, I.; Rupérez, P. High Hydrostatic Pressure Aided by Food-Grade Enzymes as a Novel Approach for Okara Valorization. Innov. Food Sci. Emerg. Technol. 2017, 42, 197–203.
  61. Ghosh, P.; Rama, C.P. Exposition on History and Potential of Supercritical Fluid Processing. In Innovative Food Processing Technologies; Knoerzer, K., Muthukumarappan, K., Eds.; Elsevier: Amsterdam, The Netherlands, 2021; pp. 515–521.
  62. Gallego, R.; Bueno, M.; Herrero, M. Sub- and Supercritical Fluid Extraction of Bioactive Compounds from Plants, Food-by-Products, Seaweeds and Microalgae—An Update. TrAC—Trends Anal. Chem. 2019, 116, 116–213.
  63. Rodrigues, L.; Silva, I.; Poejo, J.; Serra, A.T.; Matias, A.A.; Simplício, A.L.; Bronze, M.R.; Duarte, C.M.M. Recovery of Antioxidant and Antiproliferative Compounds from Watercress Using Pressurized Fluid Extraction. RSC Adv. 2016, 6, 30905–30918.
  64. De Melo, M.M.R.; Silvestre, A.J.D.; Silva, C.M. Supercritical Fluid Extraction of Vegetable Matrices: Applications, Trends and Future Perspectives of a Convincing Green Technology. J. Supercrit. Fluids 2014, 92, 115–176.
  65. Perussello, C.A.; Zhang, Z.; Marzocchella, A.; Tiwari, B.K. Valorization of Apple Pomace by Extraction of Valuable Compounds. Compr. Rev. Food Sci. Food Saf. 2017, 16, 776–796.
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