壳聚糖及UV-C处理对长山药冷害和品质的影响

为探讨壳聚糖及UV-C处理对贮藏过程中长山药冷害和品质的影响,以长山药为试验材料,采用不同浓度的壳聚糖及不同剂量的UV-C照射处理长山药块茎,对比分析长山药的冷害指数、可溶性固形物、丙二醛(MDA)、相对电导率、抗氧化酶类活性等指标的变化。结果表明,维持长山药块茎品质的壳聚糖最佳浓度为1.0%,UV-C最佳照射剂量为6 KJ·m^-2。此条件下,壳聚糖、UV-C、壳聚糖+UV-C处理都能有效降低长山药块茎的冷害指数,抑制其MDA含量和相对电导率的升高,保护膜结构的完整性,显著降低了多酚氧化酶(PPO)活性,还可以保持较高的可溶性固形物含量和过氧化物酶(POD)活性,说明这3种处理均可控制长山药冷害的发生,延长块茎的贮藏期,其中以壳聚糖+UV-C处理效果最佳。本研究结果为减缓采后长山药冷害提供了一定的理论依据。

Effects of Chitosan and UV-C Treatment on the Chilling Injury and Quality of Yam

To investigate the effects of Chitosan and UV-C treatment on the chilling injury and quality of yam, the yam was treated with different concentration of chitosan and different doses of UV-C irradiation,and the change in the index of chilling injuries,soluble solids content,MDA,electric conductivity,antioxidant enzymes activity were analyzed. The results showed that the optimum concentration of chitosan was 1.0% and the optimal irradiation dose for UV-C was 6 KJ·m^-2 for maintaining the quality of yam tuber.Under this condition, chitosan, UV-C irradiation and chitosan combined with UV-C could significantly reduced the chilling injury index and chilling injury incidence of yam,inhibited the accumulation of malondialdehyde(MDA) and the increase in membrane permeability, which also helped to maintain the film structure integrity, lower the polyphenol oxidase (PPO) activity,and maintain the high level of total soluble solids content and peroxidase (POD). It was visible that these results indicated that three kinds of treatment can markedly alleviate the chilling injury symptoms and extend the storage time of yam, and the chitosan combined with UV-C is the most effective way against chilling injury. This study provides a theoretical basis for alleviation of chilling injury of yam.