热处理对冷藏枇杷木质化及相关酶活性的影响

    Effects of heat treatment on flesh leatheriness and related enzyme activities of loquat fruits during cold storage

    • 摘要: 为阐明热处理对冷藏枇杷果实木质化败坏的影响及其机理,该研究先将枇杷果实用38℃热空气处理5 h,然后在(1±1)℃下贮藏35 d,并每隔7 d测定果实硬度、出汁率、苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)和多聚半乳糖醛酸酶(PG)等木质化相关酶活性及果胶和木质素含量的变化。结果表明,热处理可以有效控制果实硬度的上升和出汁率的下降,抑制PAL、POD和PPO活性的上升及PG活性的下降,减少原果胶和木质素的积累,保持较高的水溶性果胶含量,从而减轻冷藏枇杷果实的木质化症状,保持较好的食用品质。这些结果表明,热处理减轻冷藏枇杷果实木质化败坏的机理与其抑制木质素的合成和促进果胶物质的降解有关。

       

      Abstract: The study was conducted to investigate the effects of heat treatment on flesh leatheriness of cold-stored loquat fruits and the possible mechanisms. Freshly harvested loquat fruits were pre-treated with hot air at 38℃ for five hours and then stored at (1±1)℃ for 35 days. Fruits firmness, extractable juice rate, the activities of phenylalanine ammonium-lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO) and polygalacturonase (PG) that were related to flesh leatheriness, and contents of lignin and pectin were analyzed at seven-day intervals during storage. The results indicated that heat treatment significantly delayed the increase of fruits firmness and the decrease of extractable juice rate, inhibited the increase of PAL, POD and PPO activities and the decrease of PG activity. Meanwhile, heat treatment reduced the accumulation of lignin and protopectin and maintained higher content of water soluble pectin, thereby prevented the development of flesh leatheriness and maintained the quality of cold-stored loquat fruits. These data suggest that the reduction of flesh leatheriness by heat treatment may be related to the inhibition of lignin synthesis and the enhancement of pectin solubilization.

       

    /

    返回文章
    返回