Abstract:The effects of coating and heat treatment on aril breakdown of “Red globe” grape fruit and its relation to energy metabolism were investigated in the present study. Fruits were coated in 1% chitosan solution or heated to 45 ℃ in water, and then stored at 4±0.5 ℃. Untreated fruits were used as controls (CK). Aril breakdown index, membrane permeability, MDA content, activities of metabolism-related enzymes (H+-ATPase, Ca2+-ATPase, SDH, and CCO), ATP, ADP, AMP, total adenosine contents, and energy charge were determined during storage at seven-day intervals. The results showed that membrane integrity, energy levels, and activities of metabolism-related enzymes were decreased. However, after coating and heat treatment, these remained at a higher level than those of CK. In terms of reducing aril breakdown index, and maintaining membrane integrity and ATP level, coating treatment was significantly better than heat treatment (p<0.05). Aril breakdown indices had highly significant positive correlations (r=0.73, 0.79, p<0.01) with membrane permeability and MDA content, but were highly negatively correlated (r=-0.79~-0.54, p<0.01) with energy levels and energy charge. Aril breakdown indices had extremely significant negative correlations (r=-0.75~-0.70, p<0.01) with mitochondrial protein content and activities of metabolism-related enzymes. Aril breakdown indexes were closely related with changes in membrane integrity and activities of energy metabolism. Coating and heat treatments maintained membrane integrity and high energy levels, and also alleviated the decline of metabolism-related enzyme activities and delayed aril breakdown. Furthermore, coating treatment was better than heat treatment.
