Recommendation of Packing Method to Delay the Quality Decline of Green Tea Powder Stored at Room Temperature

摘要

The effects of packing methods on green tea powder were investigated by examining quality changes of the tea during storage at room temperature. Packings were performed in aluminium packs treated with an antioxidant, a waterproofing agent, and vacuum,respectively. Aluminium -packing without any treatment showed the green tea quality of unchanged for two months storage, after which significant decrease in the green powder tea constituents connected quality such as total nitrogen, total amino acid, tannin, caffeine, chlorophyll, vitamin C, and fatty acid were observed. However, one month longer storage period was observed in aluminium-packing treated with the antioxidant or waterproofing agent or vacuum as compared to the only aluminium packing. Thechanges in powder color of green tea were significant between the packing methods at room temperature, giving the green color index values of -14.05 and -7.02 for two and four months, respectively, resulted in the value decreased by 60% with the storageperiod. A sensuous examination for quality assay of the green tea demonstrated that aluminium-packing treated with vacuum resulted in the storage period two months longer than just aluminium-packing. This study suggested that vacuum-packing was a successful method for storage of green tea powder at room temperatures.