Abstract:

Blueberry fruits were treated with varying concentrations of calcium chloride before storage at -18 ℃ for 6
months, and changes in blueberry quality were investigated during the storage period. The results indicated that calcium
chloride resulted in a decrease in weight, firmness, total soluble solid (TSS), titratable acid, vitamin C, polyphenol and
anthocyanin in blueberry fruits during the frozen storage. Calcium chloride treatment also retarded the decrease of fruit
firmness, TSS, polyphenol, anthocyanin and vitamin C. In addition, the soluble polyphenol oxidase (PPO) activity and
soluble peroxidase (POD) activities were decreased. Calcium chloride treatment significantly inhibited PPO activity in the
later period of frozen storage, but had no significant effect on POD activity. By comprehensive analysis, 1.5% calcium
chloride treatment on quick frozen blueberry fruits presents the optimum protection effects during frozen storage.

Key words: blueberry, calcium chloride, quick frozen, frozen storage, quality