摘要
本文研究了γ辐照对苹果硬度、果胶酶活力,细胞超微结构以及挥发性成份的影响。结果表明,辐照苹果的硬度在短期(辐照后2天)内随辐照剂量的增加而下降,但是,随着贮藏时间的延长,0.3—0.9kGy辐照的苹果,其硬度比对照高。1.5kGy以下剂量辐照的苹果,其果胶甲脂酶和多聚半乳糖醛酸酶的活性与果肉硬度呈负相关,而高剂量(2.0kGy)辐照,则导致苹果的软化,使果肉细胞的细胞质和核质聚集形成颗粒,细胞膜断裂,核膜膨大,组织透性增大。0.7—2.0kGy辐照,减少了苹果挥发性成份的种类,其中四种主要成份,即乙酸乙酯、丁醇、乙酸丁酯和乙酸己酯的含量也减少,2.0kGy辐照,还使后两种主要成份完全消失。但同样剂量辐照,对上述四种物质的纯品则没有影响。
The effects of irradiation on the pectinesterase ( PE ) , polygalactu-ronase(PG)enzymatic activities, ultrastructure of cells and volatile components of apple have been studied. The results showed that the flesh firmness of irradiated apple decreased with the increasing of irradiation dosage within 2 days; it was, however, higher than that of unirradiated apple in 48 days storage; and the activities of PE, PG were inhibited by irradiation dose of 0.3 to 0.9 kGy. The negative correlations between the flesh firmness and the activities of PE, PG were observed when the dosage of irradiation was lower than 1.5 kGy.By using electron microscopic techniques,the damage of ultrastructureof cells was examined.The results showed that the breaking of cell membrane, expanding of nuclear membrane, aggregating of cytoplasm and nuclear substance were induced by 2.0 kGy irradiation.The contents of 4 important volatile components of apple such as ethyl acetate, n-butyl alcohol, n-butyl acetate and n-hexyl acetate would be decreased when fruits were irradiated with 0.7-2.0 kGy. However, irradiation has no effects on the pure chemicals.
出处
《核农学报》
CAS
CSCD
1989年第1期28-36,共9页
Journal of Nuclear Agricultural Sciences
关键词
苹果
Γ辐照
果胶酶
超微结构
Apple, irradiation, pectinase, ultrastructure,volatile component
