Phenolic Compounds from Apples: Reviewing their Occurrence, Absorption, Bioavailability, Processing, and Antioxidant Activity – a Review
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Department of Chemistry and Biodynamics of Food, Division of Food Sciences, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, ul. Tuwima 10, 10-748 Olsztyn, Poland
Department of Technology and Evaluation of Plant Products, Faculty of Biology and Agriculture, University of Rzeszów, ul. Zelwerowicza 4, 35-601 Rzeszów, Poland
Małgorzata Starowicz   

Chemistry and Biodynamics of Food, Institute of Animal Reproduction and Food Research, Tuwima, 10, 10-748, Olsztyn, Poland
Submission date: 2020-04-15
Final revision date: 2020-09-18
Acceptance date: 2020-09-18
Online publication date: 2020-10-16
Publication date: 2020-10-16
This review summarises the research on phenolic compounds in apples in relation to their geographical origin, cultivars, technological processes, and human health effects due to their antioxidant activity and bioavailability. Apples are popular among consumers and are known as a rich source of vitamins, minerals, and biologically active compounds. In this review article, we have focused on their phenolic compounds. Some epidemiological studies have confirmed the protective effects of apples against chronic diseases, which can be linked to the high content of phenolics in plant tissues and their bioavailability. However, according to the available literature, the geographical origin and variety of apples influence the content of these bioactive compounds and are highly related to their antioxidant activity fluctuation. The gathered studies have confirmed that the choice of polyphenol-rich raw material as well as proper processing are important to achieve high-quality fruit-based products with a high content of antioxidants after a few stages of production. It was proven that the processing of apples could significantly modify the content of phenolics in the finished products, including juices, concentrates, vinegars, and ciders. For instance, the use of high pressure or vacuum has been proposed as a highly potent solution in inhibiting flavonoid degradation during intensive processing. Moreover, several methods have been screened to monitor the phenolic content and antioxidant activity of apple samples, based on spectrophotometry, HPLC, LC-MS, and LC-MS/MS techniques for chemical compound separation and identification. The main assumptions of these techniques and results obtained are described in this review.
Adamenko, K., Kawa-Rygielska, J., Kucharska, A.Z., Piórecki, N. (2019). Fruit low-alcoholic beverages with high contents of iridoids and phenolics from apple and Cornelian cherry (Cornus mas L.) fermented with Saccharomyces bayanus. Polish Journal of Food and Nutrition Sciences, 69(3), 307-317.
Alam, Md.N., Bristi, N.J., Rafiquzzaman, Md. (2013). Review on in vivo and in vitro methods evaluation of antioxidant activity. Saudi Pharmaceutical Journal, 21(2), 143-152.
Arts, I.C., Hollman, P.C. (2005). Polyphenols and disease risk in epidemiologic studies. American Journal of Clinical Nutrition, 81(1), S317-S325.
Azlan, A., Kok, Y.W., Khoo, H.E. (2018). Antioxidants content and activity of polyphenol-rich mixtures. Journal of Engineering and Applied Sciences, 13(9), SI, 6973-6979
Bahukhandi, A., Dhyani, P., Bhatt, I.D., Rawal, R.S. (2018). Variation in polyphenolics and antioxidant activity of traditional apple cultivars from West Himalaya, Uttarakhand. Horticultural Plant Journal, 4(4), 151-157.
Bakir, S., Toydemir, G., Boyacioglu, D., Beekwilder, J., Capanoglu, E. (2016). Fruit antioxidants during vinegar processing: changes in content and in vitro bio-accessibility. International of Molecular Sciences, 17(10), art. no. 1658.
Bat, K.B., Vodopivec, B.M., Eler, K., Ogrinc, N., Mulič, I., Masuero, D., Vrhovšek, U. (2018). Primary and secondary metabolites as a tool for differentiation of apple juice according to cultivar and geographical origin. LWT - Food Science and Technology, 90, 238-245.
Bhagwat, S.B., Haytowitz, D.B., Holden, J.M. (2011). USDA database for the flavonoid content of selected foods. Release 3.1. Available on-line at []. Accessed 21 Janaury 2020.
Bosetti, C., Spertini, L., Parpinel, M., Gnagnarella, P., Lagiou, P., Negri, E., Franceschi, S. (2005). Flavonoids and breast cancer risk in Italy. Cancer Epidemiological Biomarkers Prevention, 14, 805-808.
Budak, N.H., Ozçelik, F., Güzel-Seydim, Z.B. (2015). Antioxidant activity and phenolic content of apple cider. Turkish Journal of Agriculture - Food Science and Technology, 3(6), 356-360.
Calderón-Oliver, M, Ponce-Alquicira, E. (2018). Fruits: a source of polyphenols and health benefits. Eds. A.M. Grumezescu, A.M. Holban, In Handbook of Food Bioengineering, Natural and Artificial Flavoring Agents and Food Dyes, Academic Press, London, United Kingdom, pp. 189-228.
Corey, M.E., Kerr, W.L., Mulligan, J.H., Lavelli, V. (2011). Phytochemical stability in dried apple and green tea functional products as related to moisture properties. LWT - Food Science and Technology, 44(1), 67-74.
Crespy, V., Aprikian, O., Morand, Ch., Besson, C., Manach, C., Demigné, Ch., Rémésy, Ch. (2001). Bioavailability of phloretin and phloridzin in rats. The Journal of Nutrition, 131(12), 3227-3230.
Del Bo, C., Bernardi, S., Marino, M., Porrini, M., Tucci, M., Guglielmetti, S., Cherubini, A., Carrieri, B., Kirkup, B., Kroon, P., Zamora-Ros, R., Liberona, N.H., Andres-Lacueva, C., Riso, P. (2019). Systematic review on polyphenol intake and health outcomes: is there sufficient evidence to define a health-promoting polyphenol-rich dietary pattern? Nutrients, 11(6), art. no. e1355.
Dhyani, P., Bahukhandi, A., Rawat, S., Bhatt, I.D., Rawal, R.S. (2018). Diveristy of bioactive compounds and antioxidant activity in Delicious group of apple in Western Himalaya. Journal of Food Science and Technology - Mysore, 55(7), 2587-2599.
Dibanda, R.F., Akdowa, E.P., Rani, P.A. Tongwa, Q.M., Mbofung C.M.F. (2020). Effect of microwave blanching on antioxidant activity, phenolic compounds and browning behaviour of some fruit peelings. Food Chemistry, 302, art. no. 125308.
Du, G.R., Zhu, Y.Y., Wang, X.Y., Zhang, J., Tian, C.R.., Liu, L., Meng, Y.H., Guo, Y.R. (2019). Phenolic composition of apple products and by-products based on cold-pressing technology. Journal of Food Science and Technology – Mysore, 56(3), 1389-1397.
Duda-Chodak, A., Tarko, T., Satora, P., Sroka, P., Tuszyński, T. (2010). The profile of polyphenols and antioxidant properties of selected apple cultivars grown in Poland. Journal of Fruit an Ornamental Plant Research, 18(2), 39-50.
Dunnick, J.K., Hailey, J.R. (1992). Toxicity and carcinogenicity studies of quercetin, a natural component of foods. Toxicological Sciences, 19(3), 423–431.
Escarpa, A., González, M.C. (2001). Approach to content of total extractable phenolic compounds from different food samples by comparison of chromatographic and spectrophotometric methods. Analytica Chimica Acta, 427(1), 119-127.
Fernández-Jalao, I., Sánchez-Moreno, C., De Ancos, B. (2019). Effect of high-pressure processing on flavonoids, hydrocinnamic acids, hydrochalcones and antioxidant activity of apple ‘Golden Delicious’ from different geographical origin. Innovative Food Science & Emerging Technologies, 51, SI, 20-31.
Ferrentino, G., Morozova, K., Mosibo, O.K., Ramezani, M., Scampicchio, M. (2018). Biorecovery of antioxidants from apple pomace by supercritical fluid extraction. Journal of Cleaner Production, 186, 253-261.
Francini, A., Sebastiani, L. (2013). Phenolic compounds in apple (Malus x domestica Borkh.): compounds characterization and stability during postharvest and after processing. Antioxidants, 2(3), 181-193.
Frank, J., Budek, A., Lundh, T., Parker, R.S., Swanson, J.E., Lourenço, C.F., Gago, B., Laranjinha, J., Vessby, B., Kamal-Eldin, A. (2006). Dietary flavonoids with a catechol structure increase α-tocopherol in rats and protect the vitamin from oxidation in vitro. Journal of Lipid Research, 47(12), 2718-2725.
George, V.C., Rupasinghe, H.P.V. (2017). Apple flavonoids suppress carcinogen-induced DNA damage in normal human bronchial epithelial cells. Oxidative Medicine and Cellular Longevity, 2017, art. no. 1767198.
Giacalone, M., Di Sacco, F., Traupe, I., Pagnucci, N., Forfori, F., Giunta, F. (2015). Blueberry polyphenols and neuroprotection. Eds. R.R. Watson, V.R. Preedy, In Bioactive Nutraceuticals and Dietary Supplements in Neurological and Brain Disease, Prevention and Therapy, 1, Academic Press, Cambridge, USA, pp. 17-28.
Gökmen, V., Serpen, A., Fogliano, V. (2009). Direct measurement of the total antioxidant capacity of foods: the ‘QUENCHER’ approach. Trends in Food Science & Technology, 20(6-7), 278-288.
Gomes, S.M.C., Ghica, M.-CE., Rodrigues, I.A., de Souza Gil, E., Oliveira-Brett, A.M. (2016). Flavonoids electrochemical detection in fruit extracts and total antioxidant capacity evaluation. Talanta, 154, 284-291.
Guo, X.F., Ruan, Y., Li, Z.H., Li, D. (2019). Flavonoid subclasses and type 2 diabetes mellitus risk: a meta-analysis of prospective cohort studies. Critical Reviews in Food Science and Nutrition, 59(17), 2850-2862.
Habanova, M., Saraiva, J.A., Holovicova, M., Moreira, S.A., Fidalgo, L.G., Haban, M., Gazo, J., Schwarzova, M., Chlebo, P., Bronkowska, M. (2019). Effect of berries/ apple mixed juice consumption on the positive modulation of human lipid profile. Journal of Functional Foods, 60, art. no. 103417.
Hamauzu, Y., Yasui, H., Inno, T., Kume, C., Omanyuda, M. (2005). Phenolic profile, antioxidant property, and anti-influenza viral activity of Chinese quince (Pseudocydonia sinensis Schneid.), quince (Cydonia oblonga Mill.), and apple (Malus domestica Mill.) fruits. Journal of Agricultural and Food Chemistry, 53(4), 928-934.
Han, M., Li, G., Liu, X., Li, A., Mao, P., Liu, P., Li, H. (2019). Phenolic profile, antioxidant activity and anti-proliferative activity of crabapple fruits. Horticultural Plant Journal, 5(4), 155-163.
Hellstrom, J.K., Torronen, A.R., Mattila, P.H. (2009). Proanthocyanidins in common food products of plant origin. Journal of Agricultural and Food Chemistry, 57(17), 7899-7906.
Hollands, W.J., Voorspoels, S., Jacobs, G., Aaby, K., Meisland, A., Garcia-Villalba, R., Tomas-Barberan, F., Piskuła, M.K., Mawson, D., Vovk, I., Needs, P.W., Kroon, P. (2017). Development, validation and evaluation of an analytical method for the determination of monomeric and oligomeric procyanidins in apple extracts. Journal of Chromatography A, 1495, 46-56.
Hollman, P.C., van Trijp, J.M., Buysman, M.N., van der Gaag, M.S., Mengelers, M.J., de Vries, J.H., Katan, M.B. (1997). Relative bioavailability of the antioxidant flavonoid quercetin from various foods in man. FEBS Letters, 418(1-2), 152–156.
Horszwald, A., Andlauer, W. (2011). Characterization of bioactive compounds in berry juices by traditional photometric and modern microplate methods. Journal of Berry Research, 1(4), 189-199.
Jacob, K., Periago, M.J., Böhm, V., Berruezo, G.R. (2008). Influence of lycopene and vitamin C from tomato juice on biomarkers of oxidative stress and inflammation. British Journal of Nutrition, 99(1), 137–146.
Jakobek, L., García-Villalba, R., Tomás-Barberán, F.A. (2013). Polyphenolic characterization of old local apple varieties from Southeastern European region. Journal of Food Composition and Analysis, 31(2), 199-211.
Jelodarian, S., Ebrahimabadi, A.H., Khalighi, A., Batooli, H. (2012). Evaluation of antioxidant activity of Malus domestica fruit extract from Kashan area. Avicenna Journal of Phytomedicine, 2(3), 139-145.
Jepson, R.G., Mihaljevic, L., Craig, J. (2004). Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews, 2, art. no. CD001321.
Jiao, X., Wang, Y., Li, Y., Lang, Y., Li, E., Zhang, X., Zhang, Q., Feng, Y., Meng, X., Li, B. (2019). Blueberry polyphenols extract as a potential prebiotic with anti-obesity effects on C57BL/6J mice by modulating the gut microbiota. Journal of Nutritional Biochemistry, 64, 88-100.
Kahle, K., Kraus, M., Richling, E. (2005). Polyphenols profiles of apple juices. Molecular Nutrition & Food Research, 49(8), 797-806.
Knekt, P., Kumpulainen, J., Jarvinen, R., Rissanen, H., Heliovaara, M., Reunanen, A. (2002). Flavonoid intake and risk of chronic diseases. American Journal of Clinical Nutrition, 76(3), 560-568.
Kolniak-Ostek, J., Oszmiański, J., Wojdyło, A. (2013). Effect of L-ascorbic acid addition on quality, polyphenolic compounds and antioxidant capacity of cloudy apple juices. European Food Research and Technology, 236(5), 777-798.
Krawitzky, M., Arias, E., Peiro, J.M., Negueruela, A.J., Val, J., Oria, R. (2014). Determination of color, antioxidant activity, and phenolic profile of different fruit tissue of Spanish ‘Verde Doncella’ apple cultivar. International Journal of Food Properties, 17(10), 2298-2311.
Kschonsek, J., Wolfram, T., Stöckl, A., Böhm, V. (2018). Polyphenolic compounds analysis of old and new apple cultivars and contribution of polyphenolic profile to the in vitro antioxidant capacity. Antioxidants, 7(1), art. no. 20.
Lee, K.W., Kim, Y.J., Kim, D.-O., Lee, H.J., Lee, Ch.Y. (2003). Major phenolics in apple and their contribution to the total antioxidant capacity. Journal of Agricultural and Food Chemistry, 51(22), 6516-6520.
Liu, Q., Tang, G-Y., Zhao, C.-N., Gan, R.-Y., Li, H-B. (2019). Antioxidant activities, phenolic profiles, and organic acids contents of fruit vinegars. Antioxidants, 8(4), art. no.78.
Lončarić A., Matanović K., Ferrer P., Kovač, T., Šarkanj, B., Skendrović Babojelić, M., Lores, M. (2020). Peel of traditional apple varieties as a great source of bioactive compounds: extraction by micro-matrix solid-phase dispersion. Foods, 9(1), art. no. 80.
Lotito, S.B., Frei, B. (2004a). Relevance of apple polyphenols as antioxidant in human plasma: contrasting in vitro and in vivo effects. Free Radical Biology & Medicine, 36(2), 201-211.
Lotito, S.B., Frei, B. (2004b). The increase in human plasma antioxidant capacity after apple consumption is due to the metabolomics effect of fructose on urate, not apple-derived antioxidant flavonoids. Free Radical Biology & Medicine, 37(2), 251-258.
Lotito, S.B., Frei, B. (2006). Consumption of flavonoid-rich foods and increased plasma antioxidant capacity in humans: cause, consequence, or epiphenomena. Free Radical Biology & Medicine, 41(12), 1727-1746.
Loung, Ch.-Y., Fernando, W., Rupasingne, H.P.V., Hoskin, D.W. (2019). Apple peel flavonoid fraction 4 suppresses breast cancer cell growth by cytostatic and cytotoxic mechanisms. Molecules, 24(18), art. no. 3335.
Lu, Y.R., Foo, L.Y. (2000). Antioxidant and radical scavenging activities of polyphenols from apple pomace. Food Chemistry, 68(1), 81-85.
Maleki, S.J., Crespo, J.F., Cabanillas, B. (2019). Anti-inflammatory effects of flavonoids. Food Chemistry, 299, art. no. 125124.
Manach, C., Williamson, G., Morand, C., Scalbert, A., Remesy, C. (2005). Bioavailability and bioefficacy of polyphenols in humans: I. Review of bioavailability studies. American Journal of Clinical Nutrition, 81, 230-242.
Maragò, E., Iacopini, P., Camangi, F., Scattino, C., Ranieri, A., Stefani, A., Sebastiani, L. (2015). Phenolic profile and antioxidant activity in apple juice and pomace: effects of different storage conditions. Fruits, 70(4), 213–223.
Martí, N., Mena, P., Cánovas, J.A., Micol, V., Saura, D. (2009). Vitamin C and the role of citrus juices as functional food. Natural Product Communications, 4(5), 677–700.
Matsuoka, K. (2019). Anthocyanins in apple fruit and their regulation for health benefits. In Flavonoid - a Coloring Model for Cheering Up Life, IntechOpen. Available on-line at: [] (accessed 11 February 2020).
Minatel, I.O., Borges, C.V., Ferreira, M.J, Gomez Gomez, H.A., Chen, Ch.-Y.O., Pereira Lima, G.P. (2017). Phenolic compounds: functional properties, impact of processing and bioavailability. Eds. M. Soto-Hernandez, M. Palma-Tenango, M. del Rosaria Garcia-Mateos, In Phenolic Compounds. Biological Activity, IntechOpen, London, UK.
Murillo, E., Britton, G.B., Durant, A.A. (2012). Antioxidant activity and polyphenol content in cultivated and wild edible fruits grown in Panama. Journal of Pharmacy & Bioallied Sciences, 4(4), 313–317.
Murphy, K.J., Walker, K.M., Dyer, K.A. (2019). Estimation of daily intake of flavonoids and major food sources in middle-aged Australian men and women. Nutrition Research, 61, 64-81.
Murtaza, A., Iqbal, A., Marszałek, K., Iqbal, M.A., Waseem Ali Sh., Xu, X., Pan, Sh., Hu, W. (2020). Enzymatic, phyto-, and physicochemical evaluation of apple juice under high-pressure carbon dioxide and thermal processing. Foods, 9(2), art. no. 243.
Naczk, M., Shahidi, F. (2004). Extraction and analysis of phenolics in food. Journal of Chromatography A, 1054(1-2), 95-111.
Ohr, L.M. (2004). Dietary antioxidants. Food Technology, 58(10), 67-74.
Oszmiański, J., Wojdyło, A. (2009). Effects of blackcurrant and apple mash blending on the phenolics contents, antioxidant capacity, and color of juices. Czech Journal of Food Sciences, 27(5), 338-351.
Oszmianski, J., Wolniak, M., Wojdylo, A., Wawer, I. (2007). Comparative study of polyphenolic content and antiradical activity of cloudy and clear apple juices. Journal of the Science and Food Agriculture, 87(4), 573-579.
Oszmiański, J., Wolniak, M., Wojdyło, A., Wawer, I. (2008). Influence of apple puree preparation and storage on polyphenols contents and antioxidant activity. Food Chemistry, 107(4), 1473-1484.
Pająk, P., Socha, R., Łakoma, P., Fortuna, T. (2017). Antioxidant properties of apple slices stored in starch-based films. International Journal of Food Properties, 20(5), 1117-1128.
Pastene, E., Troncoso, M., Figueroa, G., Alarcon, J., Speisky, H. (2009). Association between polymerization degree of apple peel polyphenols and inhibition of Helicobacter pylori urease. Journal of Agricultural and Food Chemistry, 57(2), 416-424.
Pavun, L., Usković-Marković, S., Jelikić-Stankov, M., Đikanović, D., Đurđević, P. (2018). Determination of flavonoids and total polyphenol contents in commercial apple juices. Czech Journal of Food Sciences, 36(3), 233-238.
Pires, T.C.S.P., Dias, M.I., Barros, L., Alves, M.J., Oliveira, M.B.P.P., Santos-Buelga, C., Ferreira, I.C.F.R. (2018). Antioxidant and antimicrobial properties of dried Portuguese apple variety (Malus domestica Borkh. cv Bravo de Esmolfe). Food Chemistry, 240, 701-706.
Plumb, G.W., De Pascual-Teresa, S., Santos-Buelga, C., Cheynier, V., Williamson, G. (1998). Antioxidant properties of catechins and proanthocyanidins: Effect of polymerisation, galloylation and glycosylation. Free Radical Research, 29(4), 351-358.
Porrini, M., Riso, P. (2008). Factors influencing the bioavailability of antioxidants in foods: a critical appraisal. Nutrition, Metabolism & Cardiovascular Diseases, 18(10), 647-650.
Rana, Sh., Gupta, S., Rana, A., Bushau, S. (2015). Functional properties, phenolic constituents and antioxidant potential of industrial apple pomace for utilization as active food ingredient. Food Science and Human Wellness, 4(4), 180-187.
Raphaelli, C.D., Pereira, E.D., Camargo, T.M., Vinholes, J., Rombaldi, C.V., Vizzotto, M., Nora, L. (2019). Apple phenolic extracts strongly inhibit α-glucosidase activity. Plant Foods for Human Nutrition, 74(3), 430-435.
Raudone, L., Raudonis, R., Liaudanskas, M., Viškelis, P., Pukalskas, A., Janulis, V. (2016). Phenolic profiles and contribution of individual compounds to antioxidant activity of apple powders. Journal of Food Science, 81(5), C1055-C1061.
Raudone, L., Raudonis, R., Liaudanskas, M., Janulis, V., Viskelis, P. (2017). Phenolic antioxidant profiles in the whole fruit, flesh and peel of apple cultivars grown in Lithuania. Scientia Horticulturae, 216, 186-192.
Rios, L.Y., Gonthier, M.P., Rémésy, C., Mila, I., Lapierre, C., Lazarus, S.A., Williamson, G., Scalbert, A. (2003). Chocolate intake increases urinary excretion of polyphenol-derived phenolic acids in healthy human subjects. American Journal of Clinical Nutrition, 77(4), 912–918.
Saenger, T., Hűbner F., Humpf, H.-U. (2017). Short-term biomarkers of apple consumption. Molecular Nutrition & Food Research, 61(3), art. no. 1600629.
Salucci, S., Falcieri, E. (2020). Polyphenol and their potential role in preventing skeletal muscle atrophy. Nutrition Research, 74, 10-22.
Santarelli, V., Neri, L., Sacchetti, G., Di Mattia, C.D., Mastrocola, D., Pittia, P. (2020). Response of organic and conventional apples to freezing and freezing pre-treatments: focus on polyphenols content and antioxidant activity. Food Chemistry, 308, art. no. 125570.
Scalbert, A., Williamson, G. (2000). Dietary intake and bioavailability of polyphenols. Journal of Nutrition, 130(8), 2073S-2085S.
Schempp, H., Christof, S., Mayr, U., Treutter, D. (2016). Phenolic compounds in juices of apple cultivars and their relation to antioxidant activity. Journal of Applied Botany and Food Quality, 89, 11-20.
Serra, A., Macia, A., Romero, M.P., Valls, J., Blade, C., Arola, L., Motilva, M.J. (2010). Bioavailability of procyanidin dimers and trimers and matrix food effects in in vitro and in vivo models. British Journal of Nutrition, 103, 944-952.
Shahidi, F., Ambigaipalan, P. (2015). Phenolics and polyphenolics in foods, beverages and spices: antioxidant activity and health effects - a review. Journal of Functional Foods, 18, Part B, 820-897.
Skinner, R.Ch., Gigliotti, J.C., Ku, K.M., Tou, J.C. (2018). A comprehensive analysis of the composition, health benefits, and safety of apple pomace. Nutrition Reviews, 76(12), 893-909.
Skłodowska, M., Mikiciński, A., Wielanek, M., Kuźniak, E., Sobiczewski, P. (2018). Phenolic profiles in apple leaves and the efficiency of selected phenols against free blight (Erwinia amylovera). European Journal of Plant Pathology, 151(1), 213-228.
Spranger, I., Sun, B., Mateus, A.M., de Freitas, V., Ricardo-Da-Silva, J.M. (2008). Chemical characterization and antioxidant activities of oligomeric and polymeric procyanidin fractions from grape seeds. Food Chemistry, 108(2), 519-532.
Stan, A., Bujor, O.-C., Badulescu, L. (2017). Extraction of phenolic compounds from organic dried apples: comparison between conventional, microwave- and ultrasound- assisted extraction methods. Journal of Horticulture, Forestry and Biotechnology, 21(3), 8-14.
Starowicz, M. (2019). Food and Nutritional Analysis. In Encyclopedia of Analytical Science (third edition), Elsevier, London, UK, pp. 265-270.
Sun, J., Chu, Y.-F., Wu, X.Z., Liu, R.H. (2002). Antioxidant and antiproliferative activities of common fruits. Journal of Agricultural and Food Chemistry, 50(25), 7449-7454.
Sut, S., Zengin, G., Maggi, F., Malagoli, M., Dall’Acqua S. (2019). Triterpene acid and phenolics from ancient apples of Friuli Venezia Giulia as nutraceutical ingredients: LC-MS study and in vitro activities. Molecules, 24(6), art. no. 1109.
Średnicka-Tober, D., Kazimierczak, R., Rembiałowska, E., Strok, T., Świąder, K., Hallmann, E. (2017). Bioactive compounds in organic apple juices enriched with chokeberry and green tea extract. Journal of Research and Applications in Agricultural Engineering, 62(4), 173-177.
Tappi, S., Ramazzina, I., Rizzi, F., Sacchetti, G., Ragni, L., Rocculi, P. (2018). Effect of plasma exposure time on the polyphenolic profile and antioxidant activity of fresh-cut apples. Applied Sciences - Basel, 8(10), art. no. 1939.
Tian, Y., Sun, L., Yang, Y., Gou, X., Niu, P., Guo, Y. (2018). Changes in the physicochemical properties, aromas and polyphenols of not from concentrate (NFC) apple juice during production. CyTA - Journal of Food, 16(1), 755-764.
Verdu, C.F., Childebrand, N., Marnet, N., Lebail, G., Dupuis, F., Laurens, F., Guilet, D., Guyot, S. (2014). Polyphenol variability in the fruits and juices of a cider apple progeny. Journal of the Science of Food and Agriculture, 94(7), 1305-1314.
Wang, H.L, Guo, X.B, Hu, X.D, Li, T., Fu, X., Liu, R.H. (2017). Comparison of phytochemical profiles, antioxidant and cellular antioxidant activities of different varieties of blueberry (Vaccinium spp.). Food Chemistry, 217, 773-781.
Wang, Y., Zhao, H., Deng, H., Song, X., Zhang, W., Wu, S., Wang, J. (2019a), Influence of pretreatments on microwave vacuum drying kinetics, physicochemical properties and sensory quality of apple slices. Polish Journal of Food and Nutrition Sciences, 69(3), 297-306.
Wang, J., Wang, J., Ye, J.H., Vanga, S.K., Raghavan, V. (2019b). Influence of high-intensity ultrasound on bioactive compound of strawberry juice: profiles of ascorbic acid, phenolics, antioxidant activity and microstructure. Food Control, 96, 128-136.
WHO (2009). Fruits, vegetables and NCD disease prevention. Available on-line at: [] (accessed 9 September 2020).
Whyte, A.R., Williams, C.M. (2011). The effect on memory of an acute blueberry flavonoid intervention with 8-9-year-old children. Appetite, 57(2), art. no. 567.
Williamson, G., Kay, C.D., Crozier, A. (2018). The bioavailability, transport, and bioactivity of dietary flavonoids: a review from a historical perspective. Comprehensive Reviews in Food Science and Food Safety, 17(5), 1054-1112.
Wojdyło, A., Oszmiański, J., Bielicki, P. (2010). Chemical composition, phenolic compounds and antioxidant activity of three varieties of apple from organic and conventional farming. Journal of Research and Applications in Agricultural Engineering, 55(4), 173-177.
Wojdyło, A., Oszmiański, J., Laskowski, P. (2008). Polyphenolic compounds and antioxidant activity of new and old apple varieties. Journal of Agricultural and Food Chemistry, 56(15), 6520-6530.
Wruss, J., Lanzerstorfer, P., Huemer, S., Himmelsbach, M., Mangge, H., Höglingen, O., Weghuber, D., Weghuber, J. (2015). Differences in pharmokinetics of apple polyphenols after standardized oral consumption of unprocessed apple juice. Nutritional Journal, 14, art. no. 32.
Xu, Y., Fan, M., Ran, J., Zhang, T., Sun, H., Dong, M., Zhang, Z., Zheng, H. (2016). Variation in phenolic compounds and antioxidant activity in apple seeds of seven cultivars. Saudi Journal of Biological Sciences, 23(3), 379-388.
Yuste, S., Macia, A., Ludwig, I.A., Romero, M.P., Fernandez-Castillejo, S., Catalan, U., Motilva, M.J., Rubio, L. (2018). Validation of dried blood spot cards to determine apple phenolic metabolites in human blood and plasma after an acute intake of red-fleshed apple snack. Molecular Nutrition & Food Research, 62(23), art. no. 1800623.
Yuste, S., Ludwig, I.A., Rubio, L., Romero, M.P., Pedret, A., Valls, R.M., Sola, R., Motilva, M.J., Macia, A. (2019). In vivo biotransformation of (poly)phenols and anthocyanins of red-fleshed apple and identification of intake biomarkers. Journal of Functional Foods, 55, 146-155.
Zeng, X., Du, Z., Ding, X., Jiang, W. (2020). Characterization of the direct interaction between apple condensed tannins and cholesterol in vitro. Food Chemistry, 309, art. no. 125762.
Zhang, M., Wang, Z., Mao, Y., Hu, Y., Yang, L. Wang, Y. (2019). Effects of quince pollen pollination on fruit qualities and phenolic substance contents of apples. Scientia Horticulturae, 256, art. no. 108628.
Zhou, H.C., Tam, N.F.Y., Lin, Y.M., Ding, Z.H., Chai, W.M., Wei, S.D. (2014). Relationships between degree of polymerization and antioxidant activities: a study on proanthocyanidins from the leaves of a medicinal mangrove plant Ceriops tagal. PLoS ONE, 9(10), art. no. e107606.
Zielinski, A.A.F., Alberti, A., Braga, C.M., da Silva, K.M., Canteri, M.H.G., Igarashi-Mafra, L., Granato, D., Nogueira, A., Wosiacki, G. (2014). Effect of mash maceration and ripening stage of apples on phenolic compounds and antioxidant power of cloudy juices: a study using chemometrics. LWT - Food Science and Technology, 57(1), 223-229.
Zielińska, D., Laparra-Llopis, J.M., Zieliński, H., Szawara-Nowak, D., Giménez-Bastida, J.A. (2019). Role of apple phytochemicals, phloretin and phloridzin, in modulating processes related to intestinal inflammation. Nutrients, 11(5), art. no. 1173.
Zou, Y., Wang, T., Li, Sh., Liu, Y., You, J. (2020). Dietary apple polyphenols promote fat browning in high‐fat diet‐induced obese mice through activation of adenosine monophosphate‐activated protein kinase α. Journal of the Science of Food and Agriculture, 100(6), 2389-2398.