改性聚乙烯保鲜膜包装对金红苹果抗软化效应的研究

改性聚乙烯保鲜膜包装能有效地减轻贮藏金红苹果的软化程度，降低果肉组织的呼吸强度、膜透性、可溶性果胶含量及多聚半乳糖醛酸酶活性，改性高压聚乙烯保鲜膜的保水和气调性能优于改性低压聚乙烯保鲜膜和纸塑复合膜，抗软化性能最佳。

A STUDY ON THE EFFECT OF IMPROVED PE-FRESH-FRESERVING-FILM IN RESISTING JINHONG (MALS PUMILA MILL) SOFTENING

Apple (Mains Pumila Mill) Jinhong is a new hybrid one breeded by fruit institute of Jinn Province.Jinhong fruits were packed with three kinds of PE-film (high pressure PE-film,lowpressure PE-film,complex of PE-film and a sheet of paper),and stored with the unpacked contrast in tunnel.The physical and physiological changes of fruit were studied during strage. The results showed a decrease of firmness and an increase of PG activity,respiratory intensity,soluble pectin content and membrane permeability. In the factors above,PG acted as a key enzyme to degrade pectin to seperate cells,then result in fruit softening.The noticeable event was that the soluble pectin content of Jinhong fruit stored after 92 days was lower than that of 69 days and 119 days,but the respiratory intensity varied negativiy to the ease above. This indicatedthat the products of degraded pectin could be transported from cell wall to cytoplasm,and consumed as the substrates of respiration. As the climacteric was just the 92 day after storage,thus, the consumption of products of degraded pectin was relatively increased,and the soluble pectin content.was relatively decreased.All of the softening factors could be decreased or delayed by PE-filmsealed package,the high pressure PE-film was the best one of the three kinds of pe-film in decreasing fruit softening and preserving fruit fresh.