상대습도 및 저장 온도가 분말녹차의 품질에 미치는 영향

Abstract

After storing green tea powder for three months at three different temperatures (-20, 4, and 20°C) with three different relative humidities (RHs) (23, 69, and 81%), the chemical quality was evaluated with green tea, which was prepared by soaking 1.5 g of the powder into 100 mL of distilled water at 70°C for 5 min. Total phenolic contents, total flavanol contents, and ascorbic acid contents of green tea powder stored at 4°C with 23% RH changed from 267.5, 49.4, and 24.2 mg/g to 287.1, 44.9, and 36.9 mg/g, respectively, compared to the powder before storage. EGC and EGCG, the main catechins of green tea, also changed from 16.9 and 27.3 mg/g to 24.3 and 36.5, g/g, respectively, after storage for 3 months at 4°C with 23% RH. However, when the green tea powder was stored at -20 or 20°C with higher RH such as 69 and 81%, the chemical compounds were significantly decreased. The results indicate that temperature and RH are important during storage of green tea powder, and low RH and refrigerated condition (-4°C) are preferable to increase or preserve the chemical compounds of the tea.