The Role of Major Phenolics in Apple to Total Antioxidant Capacity

Abstract

The naturally occurring phenolic compounds have received major attention in recent years as huge amounts of phenolic compounds can be extracted from fruits, vegetables and beverages that have substantial health benefits. From a physiological and metabolic aspect, phenolic compounds are vital in defence responses, such as anti-ageing, anti-inflammatory, anti-oxidant and anti-proliferative, anti-bacterial, anti-hyperlipidemic, anti-cancer, anti-diabetic, neuroprotective, cardioprotective activities. Among the fruits having a higher content of phenolic compounds, the apple (Malus Domestica) is the most widely consumed fruit in the world. Apples have a high nutritional value as it is a rich source of ascorbic acid, polyphenols and pectin. Apple peel forms a small percentage (6–8%) of the total fruit weight and contains the highest content of phenolic compounds, particularly chlorogenic acid. There are five major groups of polyphenolic compounds found in apples namely flavanols (Catechin, Epicatechin and Pyrocyanidins), phenolic compounds, phenolic acids (mainly Chlorogenic acids), dihydrochalcones (Phloretin glycosides), flavonols (Quercetin glycosides) and anthocyanins (Cyanidin). This chapter reviews the chemical properties, mode of action, types, extraction of phenolics in apples and the contribution and role of major phenolics in apples to the total antioxidant capacity.