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- 2019
恩施富硒茶硒和茶多酚的溶出特征及抗氧化活性研究
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Abstract:
以硒溶出量为指标，采用单因素和正交试验优化恩施富硒茶的冲泡工艺，并考察水质和冲泡次数对恩施富硒茶硒和茶多酚的溶出特征以及抗氧化活性的影响。结果表明：恩施富硒茶的最优冲泡条件为茶水比2∶50 (m/V,g/mL)、冲泡温度100℃、冲泡时间6 min、茶叶粒径150 μm；在最优冲泡条件下，硒的溶出量为385.57 ng/g，且一道茶汤中硒的浸出率约为12%，分别是二道茶汤和三道茶汤的3倍和6~7倍。自来水冲泡的茶汤硒溶出量要高于超纯水冲泡的茶汤，每道茶汤中四价硒所占比例为70%~90%，且溶出的硒大部分存在于茶叶溶出的小分子部分。茶多酚的溶出规律与硒相似，一道茶汤中茶多酚的溶出量达到60 mg/g，分别是二道茶汤和三道茶汤的2倍和3倍。抗氧化实验表明，富硒茶茶汤具有良好的抗氧化活性，且超纯水冲泡的茶汤抗氧化性要优于自来水；随着冲泡次数增加，茶汤的抗氧化活性也随之降低，冲泡3次即可达到对活性成分的较大利用。
The single factor and orthogonal experiments were performed to optimize the dissolution of selenium from Enshi Se enriched tea. The effects of brewing times using tap water and ultrapure water on the antioxidant activity of the tea and the dissolution characteristics of selenium and polyphenols were studied.The results showed that the ratio of tea and water 2∶50 (m/V,g/mL),brewing temperature 100℃,brewing time 6 min,tea particle size 150 μm was the optimal brewing condition of Enshi Se enriched tea. Under the optimal brewing condition,the dissolution rate of selenium was 385.57 ng/g. The selenium leaching rate of the first tea soup was about 12%,nearly 3 and 6 7 times higher than that of the second and third brewing tea soup,respectively. The general dissolution rate of selenium in tea soup using the tap water was higher than that in ultrapure water. The proportion of tetravalent selenium was 70% to 90% in each tea soup,and the selenium was mostly distributed in the small molecules of tea soluble substance. Similar trend on polyphenols was found with 60 mg/g of extraction rate in the first tea soup,2 and 3 times higher than that in the second and third tea soup,respectively. Se enriched tea soup had excellent antioxidant activity,and the antioxidant activity of tea soup brewed by ultrapure water was slightly higher than that of tap water. The antioxidant activity of tea soup decreased with the increase of the time of brewing. Brewing three times can achieve greater use of active ingredients.
