Abstract: Eight litchi cultivars from China and one from Thailand were used as materials to measure the freezing point and supercool point of fruit, and some physiological and biochemical changes of litchi fruits stored at -1℃ were also investigated. The results showed that the freezing point of the 9 cultivars ranged from -2.14 to -2.87℃. The freezing points had a positive correlation with total soluble substance of fruit but no correlation was found with single fruit weight. Ice-temperature storage combined with pericarp color retention technology made litchi fruit safe over 60 days at -1℃. The rates of respiration and ethylene releasing maintained at very lower level during storage period at -1℃, and the activities of polyphenol(PPO), peroxidase(POD) and anthocyanase were significantly inhibited, thus greatly retarding pulp senescene and pericarp browning.

Key words: Litchi(Litchi chinensis Sonn.), Freezing point, Supercool point, Ice-temperature storage