Abstract:

Grateloupia filicina polysaccharide and carrageenan were used for preparing compound coating agent on the basis of glycerin and CaCl2 as the film-forming additives. The preservative effect of compound coating agent on post-harvested Myrica rubra at ambient temperature (28－32 ℃) and relative humidity (68%－86%) was explored. Results showed that rotten fruit rate, cracking fruit rate and weight loss rate of Myrica rubra coated with edible compound film exhibited an obvious decrease. Meanwhile, respiration rate and conversion rates of total vitamin C, organic acids and other nutrients were inhibited, which resulted in an inhibition of MDA generation and reduction of anthocyanin content and relative conductivity. Activities of PPO, POD and PAL from fruits coated with edible compound film remained at a relatively low level, and the senescence process was delayed. The quality of Myrica rubra coated with film containing Grateloupia filicina polysaccharide was superior to that of fruits coated with compound film of Grateloupia filicina polysaccharide and carrageenan during storage.

Key words: Grateloupia filicina polysaccharide, carrageenan, compound coating agent, Myrica rubra, preservation