Browsing by Author "Nuanchan Phunttumatamat"

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    A Determination of the Antioxidant Activity of Proanthocyanidin of
    (Bulletin of the Department of Medical Sciences - วารสารกรมวิทยาศาสตร์การแพทย์, 2011-02-02) Penpun Wetwitayaklung; Terarat Yamrote; Nuanchan Phunttumatamat; Nuannit Kaewnuan; Puttachart Makchumnum
    The research objectives were to quantify the amount of proanthocyanidins and determinethe antioxidant property of grape seeds, cinsaut variety, cultivated in Nakhon Ratchasima province. The defattedgrape seeds powder was extracted by 2 methods. The first method was soxhlet extraction with ethanol, andthe product hereby was a precipitate of crude proanthocyanidins 0.223%. The second method was macerationwith ethylacetate and water (90:10). The extract was concentrated under vacuum and then redissolved inethylacetate. The crude proanthocyanidins were precipitated out 0.216%, when petroleum ether was added intothis crude extract solution. The antioxidant activities of these two crude proanthocyanidins were compared withthose of L-ascorbic acid and of trolox by spectrophotometry using Ferric Reducing/Antioxidant Power assay.The antioxidant activities per milligram of L-ascorbic acid, trolox and crude proanthocyanidins by soxhlet andmaceration were equal to 14.01, 10.50, 2.98 and 3.22 mmole of Fe2+, respectively. The total amounts offlavonols in crude proanthocyanidins from soxhlet extraction and maceration were 48.47% and 46.28%,respectively, calculated in catechin equivalent by vanillin-HCl assay.Key words : grape seeds, proanthocyanidins, Ferric Reducing/Antioxidant Power assay, vanillin-HCl assay