Effects of Environmental Factors on Storage Quality of Flat Green Tea and Preliminary Study on Shelf Life

According to the main environmental factors that affect the quality of green tea, the effects of temperature, humidity and light factors on the changes of physicochemical and sensory quality characteristics were studied. Besides, the accelerated shelf life test (ASLT) and Q10 model were used to predict the shelf life of flat green tea.The results showed that the content of moistureand ratio of phenoltoammonia increased significantly (P<0.05) on high-temperature, high-humidity or high-light conditions. The content of chlorophyll a, chlorophyll b, total chlorophyll and soluble sugar decreased gradually (P<0.05).The content of epigallocatechin (-) -EGC, epigallocatechin gallate (-) -EGCG, epicatechingallate (-) -ECG and total amount catechin decreased significantly (P<0.05).In addition, pearson correlation analysis showed that the sensory taste score was positively correlated with total catechin, chlorophyll and chlorophyll b (P<0.01).Principal component analysis (PCA) results showed that the order of influence of environmental factors on the quality of flat green tea was temperature>humidity>light. The accelerated shelf life test (ASLT) showed that the content of chemical components and sensory quality of flat green tea decreased, while the moisture content increased. The flat green tea showed yellow brown appearance, yellow soup and stale aroma characteristic and sensory score decreased after 3 months at 30℃ and 2 months at 40℃.Furthermore, the amount of chlorophyll a, chlorophyll b and total chlorophyll decreased. According to the Q10 model, the theoretical shelf-life of flat green were 24 months, 16 months and 8 months at 4, 10 and 20℃, respectively.This study provides theoretical basis and practical reference for the preservation of quality characteristics and optimization of storage conditions of green tea during storage.