Abstract:

The fresh-keeping effect on litchi which were storaged at 4±1℃ after drug treatment of the complex agent comprised by the mixture of antibacterial agent (natamycin, sodium diacetate) and antioxidant (tea polyphenols, ascorbic acid) with chitosan was studied. The results showed that when sorted at 4±1℃, the complex of 10g/L chitosan, 0.2 g/L natamycin, 10 g/L tea polyphenols and 19.2 g/L citric acid had an effective inhibition on the decay of litchi, the color change of its pericarp, the increase of PPO and POD activity and the decrease of the soluble solid content. Furthermore, it had a relatively satisfactory effect on improving the sensory quality of litchi. No decay was detected on the litchi coated with this complex fresh-keeping agent after storage under 4±1℃ for 18 days. Namely, through a sensory evaluation, the color of the pericarp, taste and flavor of the pulp and overall acceptability of litchi were 7.0, 6.3, 8.0, 7.0, respectively, which was significantly better than that of control group, 4.1，4.0，2.9, 3.1, respectively. Meanwhile, the activity decrease was 47.4% for PPO and 49.0% for POD compared with the control group.