干燥时间对枣多酚得率和抗氧化活性的影响

摘要

In order to improve the yield of active jujube polyphenol,it's the yield and antioxidant activity of Goutouzao and Dongzao,dried by different 50℃ hot air drying time,was studied by high performance liquid chromatography method and antioxidant activity in vitro.Test detected the yield of crude polyphenols and it's ability of scavenging DPPH · and reducing power,as well as the yield of gallic acid,protocatechuic acid,chlorogenic acid,caffeic acid,coumaric acid,ferulic acid,rutin,cinnamic acid and quercetin.The results showed that Goutouzao polyphenol yield fell from 9.205 mg/g (dried 0 h) to 8.833 mg/g (drying 48 h),the yield of fresh Dongzao jujube polyphenol decreased from 32.188 mg/g to 26.315 mg/g under the corresponding conditions.The total amount of nine kinds of free phenolic compound in Goutouzao decreases with drying time.Phenol content decreased first and then increased in Dongzao.The antioxidant capacity in vitro of Goutouzao polyphenols (dried 24h) and Dongzao polyphenols (drying 12 h) were higher than other treatments.Moreover,the latter is stronger than the former.Finally,dried Goutouzao (dry matter content,70.19％) was chosen in polyphenols extraction,polyphenols were extracted after dried by hot air for 12h at 50℃ (dry matter content,80.36％).%通过高效液相色谱法和体外抗氧化活性法研究了50℃热风干燥对狗头枣和冬枣多酚得率和体外抗氧化活性的影响.检测了粗多酚得率,没食子酸、原儿茶酸、绿原酸、咖啡酸、对香豆酸、阿魏酸、芦丁、肉桂酸和槲皮素含量,以及粗多酚清除DPPH·能力和总还原力的变化情况.结果表明,狗头枣多酚得率从9.205 mg/g(干燥0h)下降到8.833 mg/g(干燥48 h),对应条件下新鲜冬枣多酚得率从32.188 mg/g下降到26.315 mg/g.干燥处理过程中,狗头枣中的9种单体酚总量随干燥时间延长而减少;冬枣中对应的单体酚总量随干燥时间延长呈先增加后减少趋势.体外抗氧化试验中,狗头枣和冬枣多酚的抗氧化能力分别在干燥24、12h时高于各自组别中其他处理组,并且冬枣的抗氧化能力强于狗头枣.最终确定市面干制的狗头枣(干物质量为70.19％)直接用于多酚的提取,冬枣经50℃热风干燥(干物质量为80.36％)12 h后用于提取多酚.