Abstract:
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.
