烹饪方式对红枣多酚抗氧化活性的影响

研究了不同烹饪方式(高压蒸、煮及常压蒸、煮)对红枣枣皮、枣肉中多酚粗提物及4种存在形式酚酸部分的总酚含量及抗氧化活性的影响。采用Folin-Ciocalteu比色法测定其总酚含量、DPPH法和FRAP法分别评价其抗氧化活性。结果表明:高压蒸煮较常压处理红枣中的总酚含量较高,尤其是枣肉;常压煮制红枣的枣皮和枣肉中酚酸类化合物的总酚含量均最高。常压蒸制处理的红枣枣皮的DPPH·清除能力和总抗氧化能力均较强,而高压蒸制处理的红枣枣肉的DPPH·清除能力较强,常压煮制的红枣枣肉总抗氧化能力较强。红枣中总酚尤其是酚酸类化合物对其抗氧化活性起了很大的作用。红枣若采用高压烹饪方式,蒸制处理能较好地保存红枣中的酚类化合物及抗氧化活性;若采用常压烹饪方式,则煮制较好。

Effects of Cooking Treatment on Antioxidant Activity of Polyphenols in Jujube

The effects of different cooking methods(high-pressure cooking,steam and boiling under normal pressure) on the total phenolic contents and antioxidant activity of the extracts from jujube were investigated.The total phenolic contents were determined using the Folin-Ciocalteu method,and the antioxidant activity were evaluated by DPPH and FRAP assays.The results showed that the total phenolic content in jujube extracts treated by high-pressure cooking and steam is higher than that by pressure treatments,especially in the pulp of jujube.But the total phenolic acids contents in the peel and pulp of jujube treated by pressure cooking are higher.The peel of jujube treated by pressure steam exhibits the highest DPPH ? scavenging activity and total antioxidant activity.The DPPH ? scavenging activity of jujube pulp from high - pressure steam is stronger,while the total antioxidant activity of pulp from pressure cooking is higher.The total phenolics especially the phenolic acids play an important role in the antioxidant activity.If jujube is treated by high-pressure treatments,steam treatment can well preserve the phenolic compounds in jujube and their antioxidant activity.In normal pressure treatments,boiling is better.