壳聚糖涂膜处理对西葫芦冷害的影响

以西葫芦为研究对象,在5℃下采用不同质量浓度壳聚糖溶液对其进行涂膜处理,研究壳聚糖涂膜处理对西葫芦冷害发生、贮藏品质和生理生化指标的影响,为壳聚糖涂膜在控制果蔬冷害上的应用提供理论依据。结果表明,采用壳聚糖涂膜处理可以延缓西葫芦冷害的发生时间,减轻冷害程度,在贮藏第8天,水洗对照组冷害指数达到0.42,而10g/L壳聚糖处理组冷害指数只有0.08,抑制冷害效果最佳。壳聚糖涂膜还可以降低西葫芦采后呼吸强度,抑制细胞膜透性的升高和丙二醛的积累,减缓果皮叶绿素的降解,贮藏第16天,10g/L壳聚糖处理组的细胞膜相对电导率为15.04%,丙二醛含量为0.806μmol/g,叶绿素含量为0.135 3mg/g,而对照组的细胞膜相对电导率为30.23%,丙二醛含量为1.573μmol/g,叶绿素含量已降至0.053 8mg/g,壳聚糖涂膜还可以抑制CAT和POD活性下降,并降低其活性高峰。用壳聚糖处理西葫芦可以减轻其冷害发生和贮藏品质下降的程度,以10g/L壳聚糖处理组抑制冷害效果最佳。

Effect of Chitosan Coating on Chilling Injury in Summer Squash

In order to supply theory to alleviate chilling injury by chitosan coating,the effects of different concentrations of chitosan on chilling injury,storage quality and main physical-chemical characteristics of summer squash stored at 5 ℃ were investigated.The results showed that summer squash with chitosan coating treatment could postpone the appearing time of chilling injury;the injury index of comparing group was 0.42 and the injury index of disposed group with 10 g/L chitosan was only 0.08.In addition,the respiration rate was restrained,and the raise of cell membrane permeability and MDA was inhibited.At the 16th day of storage,the cell membrane permeability with 10 g/L chitosan treatment was 15.04%,the content of MDA was 0.806 μmol/g,and the content of chlorophyll was 0.135 3 mg/g,while the cell membrane permeability of the control group was 30.23%,the content of MDA was 1.573 μmol/g,and the content of chlorophyll was dropped to 0.053 8 mg/g.Moreover,chitosan coating also inhibited the activity of CAT and POD,and reduced their activity peak.The squash with chitosan treatment could reduce the occurrence of chilling injury and the decline of storage quality.The group with 10 g/L chitosan gave the best inhibition of chilling injury.