COMPOSITION OF MAJOR FLAVANONE GLYCOSIDES AND ANTIOXIDANT CAPACITY OF THREE CITRUS VARIETIES

Abstract

This paper reported on the composition of major flavanone glycosides (FGs) and antioxidant capacity of three Chinese citrus varieties during maturity, namely, Ponkan (P; citrus poonensis Hort. ex Tanaka), Satsuma mandarin (S; citrus unshiu Marc.) and Huyou (H; citrus paradisi Macf. cv. Changshanhuyou). The results showed that citrus peel is a rich source of FGs. Total penolics contents (TPC) of methanol extract of P, S and H were determined. The total antioxidant capacity (TAC) of P, S and H extracts was compared based on vitamin C equivalent antioxidant capacity by 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH·), 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS·+), reducing power and ferric reducing antioxidant power (FRAP) assay. Phenolic compounds may contribute a lot to TAC of fresh fruits, especially for unripe fruits. The correlations among TPC, DPPH·, ABTS·+, reducing power and FRAP assay were rather high (P < 0.05). PRACTICAL APPLICATION Citrus flavonoids are abundant in citrus fruits, especially FGs, such as hesperidin and naringin; and they are attracting more attentions for their biological properties and health benefits. The sun-dried citrus peels (chenpi) are usually used in the traditional Chinese medicine for high content of hesperidin. Investigation on the composition of FGs in peel and edible part of citrus fruits during maturity is necessary to establish a database for the future use in health foods and ingredients. Meanwhile, four methods were employed simultaneously to achieve a comprehensive evaluation on the antioxidant capacity of the three citrus varieties. The high antioxidant potential of the three selected citrus varieties made them desirable for dietary prevention of cardiovascular and other diseases.