两种干燥方法对不同品种荔枝多糖抗氧化及降血糖作用研究

Effects on the antioxidant and hypoglycemic activities of the different lychee polysaccharides by two drying methods

以桂味、妃子笑和糯米糍3种常见的荔枝品种为原料,研究了热风干燥和微波真空干燥对荔枝常规化学指标和荔枝多糖抗氧化能力的影响,并且通过动物实验,研究了粗多糖的降血糖作用。结果发现热风干燥桂味的多糖含量最高,妃子笑的EC50值最小、FRAP值最大。微波真空干燥妃子笑对糖尿病小鼠的降血糖作用最好。桂味和妃子笑都能够明显降低糖尿病小鼠血液中的甘油三酯含量,桂味的降低效果甚至好于阳性药物组。所有样品对糖尿病小鼠血液中总胆固醇的降低效果都不明显。总而言之,荔枝粗多糖含量与抗氧化活性及降血糖作用之间不存在正比例关系,妃子笑的抗氧化能力最强,热风干燥的荔枝多糖抗氧化性更强,但两种干燥方式荔枝多糖都有很好的降血糖效果。

Effect of air drying and microwave vacuum drying on polysaccharides of lychee with three cultivars（Guiwei,Feizixiao,Nuomici）was determined in terms of polysaccharides yield,antioxidant capacity and hypoglycemic action.The results show that Guiwei lychee dried by air drying has the highest polysaccharide content among three lychees.However,Feizixiao lychee has the lowest EC50 concentration and the highest FRAP value.Moreover,Feizixiao lychee dried by microwave vacuum drying has the best effect for improving glucose tolerance of diabetic mice.The effect of Guiwei and Feizixiao samples on decreasing TG of diabetic mice is the best and it is even better than dapagliflozin group.All lychees have no significant effect on the TC content in blood.In a word,there are also no consistency among crude polysaccharides content,antioxidant capacity and hypoglycemic effect.Feizixiao lychee has the best antioxidant capacity.Antioxidant capacity of air-dried lychee pulp is better.However,polysaccharides in air dried and microwave vacuum dried lychee both have significant hypoglycemic action.