红茶滋味成分多相分布的研究

Study on Multi-phase Distribution of Black Tea Infusion Taste Compounds

运用微滤和超滤技术将茶汤分为悬浊液、胶体相、真溶液,并分别检测了不同温度下咖啡碱、总多酚、氨基酸、总糖等滋味成分在"三相"的含量与分布比例。运用Malvern激光粒度仪对原茶汤及其分离得到的胶体相的胶体学性质进行测定,结合感官评价与茶黄素、茶红素、茶褐素的变化,将茶汤滋味成分的分布配比与胶体学性质、茶汤滋味相关联。结果表明,不同温度微滤的茶汤,滋味成分三相的分布比例有显著不同,且胶体相与真溶液的配比能影响茶汤胶体体系的粒径与电位值,同时也影响着茶汤的风味,50℃微滤茶汤获得最高感官偏好性,其两相配比分别为:咖啡碱1︰3.8、总多酚1.2︰1、氨基酸1︰7.5、总糖1︰4.3,平均粒径160 nm,Zeta电位–25.5 mV,此时的茶汤滋味醇厚、香气浓郁、体系稳定、分布均匀。

The black tea infusion was separated into three phases:suspension,colloid,and the true solution by microfiltration and ultrafiltration at different temperatures.Then the concentration and distribution proportion of caffeine,total polyphenols,amino acids,and total sugars were measured.The colloidal properties were measured by Malvern.According to the sensory evaluation and the changes in contents of theaflavin,thearubigins,theabrownin,the correlations between the distribution proportion of the taste compounds,the colloid properties and the flavor of tea infusion were established.The results revealed that the proportion of taste compounds in different phases of the tea infusion was significantly different at different temperature,and the proportion of colloid/true solution could affect the size,potential of the colloidal system and the flavor.The tea infusion acquired a best sensory score by microfiltration at50℃,while the composition distributions of colloid and true solution were1︰3.8for caffeine,1.2︰1for total polyphenols,1︰7.5for amino acids and1︰4.3for total sugars.The average particle size was160nm,and the Zeta potential was-25.5mV.The50℃filtrated tea was mellow,rich in aroma,stable,and had uniform particle size distribution.