Non-Polar Fraction Constituents, Phenolic Acids, Flavonoids and Antioxidant Activity in Fruits from Florina Apple Variety Grown under Different Agriculture Management

Abstract

The effect of agricultural management on non-polar compounds, phenolic acids, flavonoids and antioxidant properties in apple fruit of Florina variety was studied. Antioxidant activity was evaluated using four assays (DPPH, ABTS, FRAP and CUPRAC), based on different mechanisms. The current research demonstrated that organically grown apple fruits yielded significantly higher levels of total phenolics, unsaturated fatty acids and antioxidant activity than apples from the conventional conditions. Seven representatives of phenolic acids (gallic, p-coumaric, chlorogenic, vanillic, caffeic, syringic and salicylic) and four flavonoids (quercetin, rutin, catechin and epicatechin) were found in fruits. Chlorogenic, vanillic, salicylic, caffeic acids and catechin were dominated in apples grown in organic orchards. Epicatechin, gallic and syringic acids were in the highest content in conventionally grown sward apples. The highest correlation (r2>0.99) was found between total polyphenols and antioxidant activity by three methods (DPPH, ABTS and FRAP methods). As a result of the organically grown conditions, the quality of the fruits of the Florina apple variety is improved based on the accumulation of bioactive compounds with antioxidant activity. Moreover, thirty-nine volatile components (saturated and unsaturated fatty acids, fatty alcohols, phytosterols and triterpenes) were detected in non-polar apple fraction. Palmitoleic, palmitelaidic, oleic, elaidic, (13E)-octadecenoic, (13Z)-octadecenoic, (11Z)-eicosenoic and (13Z)-eicosenoic, linoleic acid and linolenic acid and ursolic and oleanolic acid acetates dominated in organic apple orchards. Therefore, organic apple provided more phenolic acids, unsaturated fatty acids, ursolic and oleanolic acid acetates and catechin for healthy human nutrition. Keywords: Apples, Antioxidants, Anthocyanins, Organical And Conventional Growing Conditions, Polyphenolic and non-polar compounds