枇杷果实采后质地的变化与调控

 以枇杷果实为材料, 通过1 - 甲基环丙烯(1-MCP) 和温度处理, 探索其对采后枇杷果实衰老过程质地的影响。结果表明, 枇杷果实采后在20℃贮藏过程中, 脂氧合酶(LOX) 活性、超氧自由基(O·2 ) 积累和苯丙氨酸解氨酶( PAL) 活性均呈峰型变化, 果肉组织相对电导率持续增加, 果实硬度趋于增大, 果肉渐趋粗糙少汁, 具有组织木质化的特征。12MCP可以显著抑制PAL和LOX活性, 减缓O·2 生成, 延缓组织衰老进程和硬度的增加。1℃低温贮藏可以有效延缓果实的衰老进程, 但会导致果实出现冷害, 其典型症状也表现出了组织木质化。采后枇杷果实衰老过程中的硬度增加与冷害胁迫下的果实组织木质化具有相似的基本特征, 但其内在机制可能不同。

Texture Changes and Regulation of Postharvest Loquat Fruit

Effects of 1-MCP and temperature treatment on texture changes of postharvest loquat fruit were investigated in the present study. During the 20℃ postharvest storage of loquat fruit, changes of LOX activities, PAL activities and O·2 accumulation showed peak-trend, tissue electric conductivity and fruit firmness increased steadily, and fresh juice percentage decreased. The changes of fruit firmness and fresh juice percentage were the characteristics of tissue lignification. Application of 1-MCP significantly inhibited PAL and LOX activities, reduced O·2 production, delayed the fruit senescence process and the increase in firmness. 1℃ temperature storage effectively retarded fruit senescence, but it induced fruit chilling injury, which also resulted in tissue lignification. The increase in firmness during postharvest loquat fruit senescence showed similar characteristic to tissue lignification of chilling injury, however, the mechanism might be different.