葡萄果实采后自溶软化与细胞膜完整性及线粒体内能量代谢的关系

研究葡萄衰老自溶软化与细胞膜完整性及能量代谢特性的关系。采后葡萄经涂膜和热处理后，低温(4±0.5) ℃贮藏，定期测定果肉自溶指数、膜透性和MDA含量、H+-ATPase、Ca2+-ATPase、SDH、CCO代谢酶活及ATP、ADP、AMP、总腺苷含量和能荷变化，以未处理为对照。结果显示：（1）果实中膜完整性、能量和能荷水平，能量代谢酶活均呈下降趋势，但涂膜和热处理要高于对照。在降低自溶软化指数、维持膜完整性和ATP水平上，涂膜显著优于热处理（p<0.05）。（2）果实自溶软化指数与膜透性和丙二醛呈极显著正相关（r=0.73，0.79，p<0.01），与线粒体蛋白量、能量代谢酶活、能量和能荷水平呈极显著负相关（r=-0.79~-0.54，p<0.01）。葡萄贮藏中自溶软化进程与细胞膜完整性和能量代谢特性紧密相关，且涂膜和热处理有利于保持细胞膜完整性，缓解能量代谢酶活下降，维持较高的能量和能荷水平，延缓自溶软化，且涂膜效果优于热处理。
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.