Abstract: The fresh-keeping effects of chitosan, alginate, nisin and lysozyme on Malu grapes during 4 ℃ storage were compared by determining their sensory quality, weight loss, hardness, respiration rate, vitamin C content, soluble solid content and SOD activity. The results indicated that chitosan-coating treatment had the best preserving effect on the sensory quality of Malu grapes. The weight loss, vitamin C content, soluble solid content, hardness and SOD activity of chitosan-treated grapes after 25 days of storage were 9.34%, 2.3 mg/100 g, 12.1%, 1027.59 kg/cm2 and 87.3 U/g, respectively. Meanwhile, the respiration intensity exhibited a significant decrease when compared with other treatment groups.

Key words: grape, preservation, coating, chitosan