STABILITY OF METHANOLIC EXTRACT ACTIVITY FOR LEAVES, PEELS AND CITRUS SEEDS UNDER UV IRRADIATION

摘要

Grapefruit {Citrus paradise Macf.) (gr); Valencia orange (C. sinensis Osbeck) (vi); Sour orange (C. aurantium L.) (lr); Lemon (C. Union L.) (ad); Balady mandarin (C. reticulate Blanco) (y); Balady orange (C. sinensis Osbeck) (or) methanolic HC1 extracts have been analyzed for antioxidative properties in their leaves L, peels P and seeds S. For the last two citrus, only leaves were extracted and evaluated. The results showed that grapefruit leaves, lemon seeds and Valencia peel extracts have the highest antioxidative property (AOA). Comparing phenol content, lemon leaves, grapefruit seeds and sour orange peel extracts have the highest phenolic amounts of all analyzed samples. In spite of that citrus seeds contain the lowest mean phenols amounts, they showed mean AOA more than 93% comparing to that for control. The chemical composition was investigated using GC-MS for the citrus seed methanolic extracts (SME). Three major peaks were detected and identified as hexadecanoic acid methyl ester (I), flavanone derivatives specifically a pentahydroxy dimethoxy flavone (II), and Kaempferide (III) a methoxy derivative. The grapefruit seed methanolic extract has the highest amount of compounds (I, III). Valencia seed extract has the highest amount of compound (II). Valencia seed extract has the lowest content of compounds (I, III) and the lemon seed extract has the lowest content for compound (II).