Xiao Yue, Wu Yanping, Zhong Kai, Gao Hong
College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University Chengdu 610065 China
Key Laboratory of Food Science and Technology of Ministry of Education of Sichuan Province, Sichuan University Chengdu 610065 China.
RSC Adv. 2019 Dec 13;9(70):41269-41279. doi: 10.1039/c9ra07655g. eCollection 2019 Dec 9.
Laochuancha is an ancient tea plant originating from the Mingshan district of Ya'an city, Sichuan province, China, which is used to produce tea products with excellent quality. Mingshan Laochuancha green tea (MLGT) is a type of green tea manufactured from Laochuancha tea leaves. Currently, not much is known regarding the chemical compositions of MLGT and its bioactivity. Herein, the present study explores, for the first time, the chemical compositions and hypolipidemic activity of MLGT. It was observed that K was the most abundant element of 26.58 mg g, and contents of toxic As, Cd, Cr and Pb elements were all below concentration limits. Alcohols (55.65%) were the main volatiles, and numerous volatiles with chestnut-like aroma were detected. Total content of 21 amino acids was 28.61 mg g, and amino acids with velvety-like and umami taste totally accounted for 65.39%. The high content of amino acids and low ratio of polyphenols to total amino acids were attributed to strong umami and mellow taste of MLGT. Moreover, catechins and alkaloids were abundant in MLGT, where EGCG (85.82 mg g) and caffeine (33.78 mg g) were at highest content. Analyses of chemical compositions revealed excellent quality of MLGT. Correspondingly, MLGT showed potent hypolipidemic activity, and water extract of MLGT at 200 μg mL significantly reduced lipid level to 43.06% of high-fat zebrafish. Results firstly revealed the quality characteristics of MLGT and provided further insights into bioactivity of Laochuancha.
老川茶是一种原产于中国四川省雅安市名山区的古老茶树品种，用于生产品质优良的茶叶产品。名山老川茶绿茶（MLGT）是一种由老川茶茶叶制成的绿茶。目前，关于MLGT的化学成分及其生物活性了解不多。在此，本研究首次探索了MLGT的化学成分和降血脂活性。结果表明，钾是含量最丰富的元素，为26.58毫克/克，有毒元素砷、镉、铬和铅的含量均低于浓度限值。醇类（55.65%）是主要挥发性成分，并检测到许多具有类似栗子香气的挥发性成分。21种氨基酸的总含量为28.61毫克/克，具有天鹅绒般口感和鲜味的氨基酸占总量的65.39%。氨基酸含量高以及多酚与总氨基酸的比例低，使得MLGT具有浓郁的鲜味和醇厚的口感。此外，MLGT中儿茶素和生物碱含量丰富，其中表没食子儿茶素没食子酸酯（EGCG，85.82毫克/克）和咖啡因（33.78毫克/克）含量最高。化学成分分析表明MLGT品质优良。相应地，MLGT表现出较强的降血脂活性，MLGT水提取物在200微克/毫升时可使高脂斑马鱼的血脂水平显著降低至43.06%。该研究首次揭示了MLGT的品质特征，并为老川茶的生物活性提供了进一步的见解。
