温度补偿处理和低温贮藏对绿茶保鲜效果的影响

Effect of Temperature Compensation Treatment and Low-temperature Storage on the Preservation of Green Tea

以西湖龙井为原料,设定温度补偿处理及3种不同的贮藏温度(-20、-5和4℃)共6个组合,分别在贮藏3、6、12个月取样,测定样品含水率、茶多酚、氨基酸、叶绿素和维生素C等成分含量,并进行感官审评,研究温度补偿处理、贮藏温度和时间对绿茶保鲜效果的影响。结果表明,随着贮藏时间的延长,叶含水率逐渐上升,温度补偿处理组合显著低于无温度补偿处理,不同贮藏温度间差异不显著;茶多酚、叶绿素a、叶绿素总量和Vc等含量呈下降趋势,氨基酸呈先升后降的趋势,叶绿素b较稳定,不同贮藏温度间差异不显著,温度补偿处理可显著减少上述品质物质的损失;绿茶感官总分随着贮藏时间的延长下降,温度补偿处理组合可显著保留绿茶原有的品质,储藏12个月感官总分均在83.00分以上,3个低温对绿茶保鲜影响不显著,故4℃储藏并进行温度补偿处理最有利于绿茶保鲜。

Using West Lake Longjing tea as the raw material, a total of six treatments combining three different storage temperatures（-20 ℃,-5 ℃, and 4 ℃） with or without temperature compensation were carried out, and samples were collected for analysis after 3, 6, and 12 months of storage, respectively. The contents of moisture, polyphenols, amino acids, chlorophyll, vitamin C, and other components in the samples were measured, and sensory evaluation tests were performed to study the effects of temperature compensation treatment, storage temperature, and time on the preservation of green tea. Consequently, with increasing storage time, the moisture content of tea increased gradually, where that of the sample treated with temperature compensation was significantly lower than that of the sample without this treatment, but the differences among different storage temperatures were not significant. The polyphenol, total chlorophyll, chlorophyll a, and vitamin C contents decreased gradually; the amino acids first increased and then decreased in amount; and the chlorophyll b level was relatively stable. Differences among different storage temperatures were not significant, and the temperature compensation process could significantly reduce the loss of the above quality substances. Without temperature compensation, the sensory scores of green tea decreased gradually with increasing storage time. However, combined with temperature compensation, the three temperatures could effectively retain the original quality of the tea, where the total sensory scores were all above 83.00 points after 12 months of storage. The three low-temperature treatments alone did not affect the preservation of green tea significantly. Therefore, 4 storage with temperature compensation was ℃ concluded to be the most conducive to the preservation of green tea.