红星苹果和肥城桃果实软化的酶学基础

以红星苹果穴Malusdomesticacv.Starking雪和肥城桃穴Prunuspersicacv.Feicheng雪果实为试材,结合乙烯利和1-甲基环丙烯(1-MCP)处理,分别研究了2者软化的酶学基础,并就其差别作了探讨。结果表明:红星果实软化中起主要作用的酶为内切和外切多聚半乳糖醛酸酶(endo-和exo-PG);肥城桃果实软化的前20d则以纤维素酶(EGase)为主,20d后软化以endo-PG为主。研究同时发现,脂氧合酶(LOX)在这2种果实软化的启动阶段都起了明显的促进作用。1-MCP通过对红星果实中PG、肥城桃果实贮藏前期EGase和后期endo-PG活性的抑制,以及对2者软化启动阶段LOX活性的抑制,延缓了果实硬度的下降。

Enzyme mechanism of fruit softening of apple cultivar Starking and peach cultivar Feicheng

Study was conducted with the treatments of Ethrel and 1-MCP, to the fruit of apple cultivar Starking (Malus domestica cv. Starking) and peach cultivar Feicheng (Prunus persica cv. Feicheng) for studying the enzyme mechanism of fruit softening. Results showed that the key enzymes involved in fruit softening in Starking apples were endo- and exo-PG; while for Feicheng peach cultivar, EGase acted mainly in the first twenty days in storage, and the PGase did after twenty days. Results also showed that LOX significantly accelerated the initiation of softening in both materials. By using 1-MCP to inhibit the PG activity in Staking apples, the EGase activity before the 20th day and endo-PG after the 20th day in Feicheng peach, and LOX activity in the initiation phase of both materials, the fruit firmness was prolonged.