【摘要】 为了开发先进的茶多糖提取方法,采用响应面实验优化了亚临界水法提取茶多糖的工艺,并对提取的茶多糖的化学组分、单糖组成进行了简单分析,对其抗氧化活性及DNA损伤的保护活性进行了评价。结果表明,亚临界水法提取茶多糖的最佳工艺条件为液料比为30:1 mL/g、亚临界温度150℃、亚临界时间12min,在此条件下粗茶多糖得率为(5.86±0.23)%,约为传统的热水浸提法得率[(2.917±0.21)%]的2倍,该结果表明亚临界水法提取茶多糖是一种高效的提取技术。所提取的茶多糖中糖含量为57.82%、蛋白含量为10.14%、糖醛酸含量为8.31%。茶多糖主要由阿拉伯糖、葡萄糖、半乳糖、半乳糖醛酸组成,各单糖之间摩尔质量比为0.20:4.88:0.32:0.13。此外,亚临界水法提取的茶多糖能保持与传统热水浸提法相当的清除羟基和ABTS自由基的能力,很好地保持了茶多糖良好地生物活性。DNA损伤的保护试验表明,茶多糖对DNA损伤具有良好的保护性能。因此,亚临界水法提取茶多糖具有广阔的应用前景。更多还原

【Abstract】 In order to develop an advanced method to extract tea polysaccharide, in this work, the tea polysaccharides were isolated by subcritical water method using response surface methodology, the chemical composition and monosaccharide composition of the extracted tea polysaccharide were analyzed, its antioxidant activity and DNA damage protection activity were evaluated. The results showed that the optimum conditions for the extraction of tea polysaccharide by subcritical water method were the liquid to material ratio of 30:1 mL/g, the subcritical temperature of 150 ℃ and the subcritical time of12 min. Under the optimal extraction conditions, the tea polysaccharide yield was(5.86±0.23)%, which was twice the rate of traditional hot water extraction [(2.917±0.21)%]. The obtained tea polysaccharide contained 57.82% sugar, 10.14% protein and 8.31% uronic acid. Sugar fraction was composed of arabinose, glucose, galactose, galacturonic acid, and the molar mass ratio was 0.20:4.88:0.32:0.13. In addition, the tea polysaccharide extracted by the subcritical water method can maintain the ability to scavenge hydroxyl and ABTS free radicals, which is equivalent to the traditional hot water extraction method. However, the extraction efficiency of the former is much higher than that of the latter. The DNA damage protection test showed that the tea polysaccharide also presented excellent DNA protection and repairing performance. Therefore, subcritical water extraction of tea polysaccharides would possess broad application prospects.更多还原