| Many studies have shown that the basic composition and the physiological activity of grapes were closely related to their varieties and growth environment. In this paper, the skins of Red Globe, Summer Black and Centennial Seedless from the main four producing grapes areas (Binchuan, Yuxi, Yuanmou and Mile) in Yunnan was used as the material, its nutraceutical properties were analyzed. Then the composition of monosaccharide, fatty acids and polyphenols were analyzed. Finally, The antioxidant activity of grape skin extracts of Red Globe, Summer Black and Centennial Seedless from four regions were evaluated by DPPH, ABTS radical scavenging capacity and reducing power (FRAP), in the hope of providing a theoretical basis for the rational utilization of grape skins resources. The major findings were presented as follows:1. The content of basic ingredients in skins of Red Globe, Summer Black and Centennial Seedless from the main four producing grapes areas were variable. The contents of total sugar and fat in the grape skins were high. The content of total sugar and crude fat in Summer Black, Red Globe and Centennial Seedless grape skins were 13.07%～14.74%,10.00%～13.21% and 8.48%-11.94%(FW); 1.22%-4.61%, 1.50%-3.67% and 1.43%-2.94%(DW), respectively. The basic ingredients of the same species were variable, due to the impact of the altitude, temperature, sunlight and other factors and environmental differences.2. The monosaccharide composition of Red Globe, Summer Black and Centennial Seedless skins from the main four producing grapes areas were arabinose, galactxironic acid, galactose, mannose, glucose, rhamnose, xylose. It was consistented with the main monosaccharide composition of the grapes, but because of different grape varieties, the content of all kinds of monosaccharide were variable. Among the seven kinds of monosaccharides, the levels of glucose (117.02～228.23 mg/gDW) was much higher than other monosaccharides, as the main monosaccharide in grape skins. The monosaccharides content of the same species were variable, due to the impact of environmental differences. The monosaccharides content in Red Globe, Summer Black and Centennial Seedless skins were found a certain order, but the Sorting is not universal. The fatty acid composition of Red Globe, Summer Black and Centennial Seedless skins from the main four producing grapes areas were oleic acid, linoleic acid and palmitic acid, and other fatty acid content and composition were variable. The unsaturated fatty acid content of Red Globe, Summer Black and Centennial Seedless skins 62.51%～89.55%,77.42%-84.6% and 57.41%～87.61%, respectively. Fatty acids in grape skins have been influenced by different areas, the proportion of unsaturated fatty acids were very widely. The content of unsaturated fatty acids in grape skins were very highly, they were very nutritional. Therefore, the grape skins can be used as a potential oil resources to be exploited.3. The total phenolic and anthocyanin content of Red Globe, Summer Black and Centennial Seedless skins from the main four producing grapes areas of descending order were Summer Black> Centennial Seedless> Red Globe; Summer Black> Red Globe>Centennial Seedless. The total phenols and proanthocyanidins content of the same species were variable. Rutin and catechin were main components of phenolics in all grape skins. The rutin content of Red Globe, Summer Black skins from the main four producing grapes areas of descending order were Yuanmou>Binchuan>Mile> Yuxi. The total phenolic content and phenolic species of Summer Black (38.46-57.77 mgGAE/g DW) was higher and abundant. The total phenolic content and phenolic species of Red Globe (11.92-20.96 mgGAE/g DW) was lower and less. The peel polyphenols has high antioxidant activity with IC50 values were 12.95-14.68 for DPPH,8.63～11.11μg/mL for ABTS and 29.35-37.15μg/mL for FRAP. The DPPH free radical-scavenging activity of the vitamin C(6.21μg/mL) were better than all grape skin extracts. The ABTS radical-scavenging activity of all grape skin extracts were better than Trolox (16.42μg/mL). The ferric reducing antioxidant power of Summer Black and Centennial Seedless skin extracts from the main four producing grapes areas were better than the vitamin C(6.21μg/mL). In different systems, the antioxidant capacity of peel polyphenols extracts were variable, which may be related to the different content and composition of polyphenol extracts.
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