摘要
茶树起源于中国,茶叶是世界三大饮品之一。茶叶中富含茶多酚、蛋白质及氨基酸、生物碱、芳香族化合物、糖类、类脂化合物、维生素、无机物、叶绿素、酶等多种化合物。它们经过非发酵、微发酵、半发酵、全发酵及后发酵工艺,萎凋、杀青、揉捻、发酵、干燥等处理后,由于温度、压力、酶及微生物的作用,儿茶素在多酚氧化酶、过氧化物酶等的氧化聚合下分别形成茶黄素、茶红素、茶褐素等茶色素;β-D-糖苷类等香气前驱体在β-葡萄糖苷酶、β-樱草糖苷酶的作用下水解生成相应的醇类等香气物质;蛋白质水解成氨基酸,并形成不同的手性对映体,所以赋予茶叶特有的颜色、香气、滋味、外形以及其抑菌、抗病毒、抗氧化、防衰老、增强机体免疫、防癌抗癌、预防心脑血管疾病等功效,进而形成绿茶、白茶、黄茶、青茶、红茶、黑茶六大茶系。本文从茶叶成品色、香、味等关键组分入手,阐述其在加工过程中的变化规律和关键技术调控的相关性及存在问题,并探讨它们的形成机理,为提高茶叶品质提供理论依据。
Tea has originated from China,and it is one of the three world＇s popular beverage.A variety of compounds,such as polyphenols,proteins,amino acids,alkaloids,aromatic compounds,carbohydrates,lipids,vitamins,minerals,chlorophyll,enzymes,were rich in tea.After being non-fermented,slightly fermented,semi-fermented,fermented and secondary fermented which include withering,fixing,rolling,fermentation and drying treatment,catechins were oxidized and polymerized to theaflavins,thearubigins and theabrownin by polyphenol oxidase and peroxidase because of the effect of temperature,pressure,enzymes and microorganisms.In addition,aroma precursors,β-D-glycosides were hydrolyzed into the correspongding alcohols and other aroma substances under the action of β-glucosidase andβ-primeverosidase.Proteins were hydrolyze into amino acids and further formed different chiral enantiomers.These would endow the unique color of tea,aroma,taste and appearance.Tea has many functions,such as antibacterial,antiviral,antioxidant,anti-aging,anti-cancer,immune enhancement,prevented of cardiovascular disease and so on.Now tea was classified into green tea,white tea,yellow tea,oolong tea,black tea and puerh tea.This paper explained the relevance and problems between the change regulation and technical control in the process from the key components of tea such as color,aroma and flavor.Moreover,the formation mechanism to provide a theoretical basis for improving the quality of tea was also discussed.
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2011年第9期176-180,共5页
Journal of Chinese Institute Of Food Science and Technology
基金
国家自然科学基金项目(20976138
20576002)
关键词
发酵
茶色素
酶
茶多酚
茶氨酸
咖啡碱
fermentation
tea pigments
enzyme
theanine
caffeine
