Synergy Research and Development Center, Synergy Flavors, Inc., 2991 Hamilton-Mason Road, Hamilton, Ohio 45011, United States.
J Agric Food Chem. 2012 Nov 28;60(47):11793-9. doi: 10.1021/jf303555f. Epub 2012 Nov 16.
Tea creaming is the development of a cloudy or hazy appearance in tea and ready-to-drink tea products on cooling and is highly undesirable in the tea beverage industry. Commonly associated with fermented black or oolong teas, the objective of this study was to investigate the physicochemical mechanism of the formation of tea cream in nonfermented green tea (Camellia sinensis) and a caffeine-containing botanical tea from yaupon holly (Ilex vomitoria) that is free of catechin-based polyphenolics. Four tea-creaming activators (phenolics, soluble protein, caffeine, and metal ions) were added to tea infusions as well as decaffeinated teas created by chloroform extraction. Tea-creaming activators increased the weight and turbidity of both teas with the exception of soluble protein addition (as bovine serum albumin) to green tea, whereas the greatest increase in turbidity occurred with the addition of metal ions in green tea. Tea creaming was equally developed at three incubation temperatures (4, 25, and 40 °C) in both teas, but tea-creaming compositions in each tea were different at the incubating temperatures. The antioxidant capacity of each tea was lowered after creaming due to the loss of antioxidants that participated in tea cream formation.
茶乳状液是指在冷却过程中茶和即饮茶产品出现浑浊或雾状的现象，这在茶饮料行业是极不受欢迎的。茶乳状液通常与发酵黑茶或乌龙茶有关，本研究的目的是调查非发酵绿茶（Camellia sinensis）和不含儿茶素类多酚的咖啡因植物茶冬青（Ilex vomitoria）中茶乳状液形成的理化机制。将四种茶乳状液形成激活剂（酚类、可溶性蛋白、咖啡因和金属离子）添加到茶浸提液中，以及用氯仿萃取制成脱咖啡因茶。茶乳状液形成激活剂增加了两种茶的重量和浊度，但除了将牛血清白蛋白添加到绿茶中外，可溶性蛋白的添加则没有增加（as bovine serum albumin），而在绿茶中添加金属离子则会引起最大的浊度增加。在两种茶中，乳状液在 4、25 和 40°C 的三个孵育温度下同样发展，但在每个孵育温度下，每种茶的乳状液组成不同。由于参与茶乳状液形成的抗氧化剂的损失，每种茶的抗氧化能力在乳状液形成后都降低了。
