Effects of β-Cyclodextrin and Sodium Ascorbate on the Chemical Compositions and Sensory Quality of Instant Green Tea Powder during Storage

The physicochemical changes of the instant green tea powders added with β-cyclodextrin and sodium ascorbate stored at 4°C and 25°C were investigated by determining moisture, polyphenols, caffeine, amino acids, catechins, color, sensory quality, and the total microbial count. The results showed that addition of both β-cyclodextrin (6%, w/w) and sodium ascorbate (2%, w/w) reduced the changes of moisture, polyphenols, and catechins contents, helped to maintain the sensory quality, and limited the microbial count. The low temperature (4°C) was also found to maintain the sensory quality and limit of the microbial count of instant green tea powder. The combination of low temperature and addition of β-cyclodextrin with sodium ascorbate were the best treatment for the storage of instant green tea powder. These results could provide useful information for the quality improvement of instant green tea powder during storage.