【作者】 吴雅红；

【导师】 罗宗铭； 唐维学；

【作者基本信息】 广东工业大学 ， 化学工程， 2005， 硕士

【摘要】 研究了绿茶饮料的制备条件,得到最佳的浸提条件为:浸提时间10min,水茶比为100:1,浸提温度90℃,浸提pn为5.5～6.0。通过对比单一的三聚磷酸钠(STPP)、六偏磷酸钠(SHMM)、β—环状糊精(β-CD)等作澄清剂,提出了采用STPP:SHMP:β-CD=1:1:2配比的复合澄清剂,加入量为0.4g/L时对茶汤进行澄清,可获得良好的澄清效果。采用超声波及微波杀菌替代传统高温灭菌技术,对茶汤进行了灭菌处理,结果表明,超声波及微波灭菌都能彻底杀死茶饮料中的细菌和真菌,与高温灭菌相比,超声波和微波灭菌对饮料品质影响较小,茶多酚保留最多,褐变与沉淀最少,是茶饮料最佳灭菌技术之一。实验证明了茶汤易形成茶乳酪的主要原因是茶多酚、咖啡碱、蛋白质和金属离子等的相互作用结果,它们之间通过多酚类物质的酚羟基,咖啡碱的酮氨基和蛋白质的肽键形成氢键,互相凝聚而使粒径增大,从而使茶汤变浑浊。在这茶乳酪沉淀的形成过程中,茶汤中的主要成分茶多酚和茶碱类物质的互相作用是主要的,蛋白质与茶多酚作用也不可忽视,解决茶乳酪沉淀的有效手段是复合澄清剂的协同澄清作用。更多还原

【Abstract】 The preparation conditions of green-tea beverages was studied. The results show that the optimal extraction conditions are: extraction time is 10 min.; the ratio of water and tea is100:1; extraction temperature is 90℃ ; extraction pH is about 5.5-6.0. The better clarify effect was achieved with using multiple clarificant (STPP: SHMP: β-CD=1: 1: 2; addition:0.4g/L) after comparison of mono-clarificant such as STTP, SHMP, β -CD. Ultrasonic and Microwave sterilization was used to substitute the traditional high-temperature method. The results of tea sterilization declared that ultrasonic and microwave could thorough kill bacillus and eumycetes and it has less influence on the tea quality than the high temperature way. Maximum Tea polyphenols could be reservered and least browning and precipitate were formed in the process. Therefore, ultrasonic and microwave sterilization is one of the best tea sterilization methods. The experiments show that the main reason that the Tea Cream were easily formed in the tea infusion is the reaction of Tea polyphenols, caffeine, protein and metallic ion. H-bonds were formed between phenol hydroxyl group in phenol chemicals, keto-amino group in caffeine and peptide linkage of protein. Co-acervation makes particle larger and tea turbidity. The main react is the interaction between main components Tea polyphenols and caffeines, but the reaction of protein and Tea polyphenols could not be ignored. An effective way to solve the problem of Tea polyphenols precipitate is using multi-clarificant in the tea clarify process.更多还原