Abstract:

Influences of NO on active oxygen metabolism and relevant quality of Chinese Bayberry (Myrica rubra) fruits were studied to provide scientific basis of NO application in fresh preservation. Fruits of Chinese Bayberry were immersed with 0,10,25,and 50 μmol ·L^-1 sodium nitroprusside(NO donor) respectively for 2 hours,and then stored for 16 d at (0±0.5)℃. Active oxygen production,relative electric conductivity,MDA content, enzymatic activity of SOD,CAT and POD and decay index were measured thereafter in every 4 days. The results showed that NO from 25 μmol ·L^-1 SNP significantly decreased the decay of Chinese Bayberry and inhibited the decline of vitamin C,titratable acid,and total sugar compared with the control fruits. NO treatment maintained significantly higher levels of SOD,CAT and POD activities of Chinese Bayberry,and inhibited the increase of H₂O₂,superoxide radical production,relative electric conductivity and MDA content. This study suggests that NO could maintain the balance of active oxygen metabolism in Chinese Bayberry,and thereby delaying fruit senescence and inhibiting fruit decay.

Key words: Chinese Bayberry (Myrica rubra), nitric oxide, metabolism of active oxygen, decay, physiological index