Nutraceutical Properties of Apples and Derived Products (Pomace, Seeds, Peels)

Abstract

REV.CHIM.(Bucharest)♦ 70♦ No. 3 ♦ 2019 934 Secondary metabolites Apples are well-known and widespread fruit of the genus Malus (about 25 species) belonging to the family Rosaceae. Apples (Malus domestica Borkh) are commonly consumed as unprocessed fresh fruit, and fresh apples are available worldwide all year round [54]. Apple production is one of the most widespread agrifood activities worldwide, with an estimated volume of USD 76.2 million tonnes in 2017/18 [60]. An important part of this production is destined to elaborating juice and derivatives such as soft drinks, ciders, vinegars etc. [48]. Secondary metabolites are natural chemical compounds that plants produce to protect themselves against other living and natural conditions. Phenolic compounds are the most important secondary compounds of the derivatives of pentose phosphate, shikimate and phenylpropanoid pathways in plants and are the most abundant compounds among phytochemicals [13, 44]. These components have biological effects such as antioxidant activity. By recycling the waste fruit pulp in the idle state, these valuable secondary metabolites will provide significant resource opportunities in terms of both the health and medicinal sectors [13]. Their use in the pharmaceutical and food-nutrition sectors is increasing due to the absence of side effects. Polyphenols are considered as antioxidants, metal chelators, antimutagens and anticarcinogens, antimicrobial agents and clarifying agents [21]. Several factors affect the phenolic content of a fruit including variety, degree of ripeness, agricultural treatments, harvesting time and processing and storage conditions [66]. Apple polyphenols have been demonstrated to have potential beneficial effects on health, such as exhibiting antioxidant activity [1, 9, 13, 17, 28, 51], antibacterial effect [3, 8], anti-tumor properties and inhibition of carcinogenesis in skin, mammary, lung, colon etc. [9, 10, 23, 31, 50, 55], reducing the risk of cardiovascular disease [10, 11, 24, 31], anti-inflammatory properties [26, 39], antidiabetes properties [6, 25] and anti-obesity effect [36, 69]. Apple polyphenols may also have positive role on Alzheimer’s disease [13]. Due to of these multiple benefits for human health, apple polyphenols attracted significant attention in the scientific field [7].