辐照对青花菜生理生化指标及保鲜效果的影响

Effects of irradiation on preservation and physiological-biochemical index of Brassica oleracea

用0.08mm 厚的聚乙烯薄膜袋包装青花菜, 经0.5、1.5和2.5 kGy(千戈瑞)3个剂量60Co-γ射线辐照,室温12～21℃贮藏。结果显示,2.5 kGy剂量辐照对青花菜的保鲜效果最佳,室温下放置7d,仍然保持鲜绿,而对照组3d 已全部变黄,无商品价值。辐照后立即对2.5kGy处理组的青花菜进行生理生化分析,其蛋氨酸含量、乙烯释放率、呼吸强度等指标均比对照组显著降低;叶绿素、花青素、维生素C、还原糖及蛋白质含量等指标与对照组相比较变化不大。辐照保鲜7d 后,乙烯释放量、呼吸强度及蛋氨酸含量都升至辐照前的水平;蛋白质、维生素C、还原糖、叶绿素和花青素含量比对照组高。由此表明,辐照造成的生理损伤已修复,不宜再继续贮藏。

Treated with 60Co-γ irradiation at 0.5kGy, 1.5kGy and 2.5kGy, respectively, Brassica oleracea packed with 0.08mm polythene plastic was stored at 12-21℃. The results showed that 2.5kGy irradiation gave the best result for preservation and Brassica oleracea kept fresh after 7-day storage while the control all turned yellow and lost commercial value. The physiological-biochemical change of Brassia oleracea treated with 2.5kGy irradiation was also analyzed. Results were as follows: the contents of Methionine(Met), ethylene production and respiratory intensity decreased by 72.23%, 72.41% and 71.95%, respectively; the contents of chlorophyll, anthocyania, Vit C, reducing sugar and protein had no much change compared to those of the controls. 7 days after irradiation treatment, the contents of Met, ethylene production and respiratory intensity increased to the levels as before and the contents of chlorophyll, anthocyania, Vit C, reducing sugar and protein were higher than those of the controls.