壳聚糖/柠檬酸复合涂膜对胡萝卜的保鲜效果

目的研究壳聚糖和柠檬酸复合涂膜对胡萝卜保鲜效果的影响,为胡萝卜采后保鲜贮藏提供新途径。方法以胡萝卜为实验材料,采用壳聚糖(质量分数为1%)涂膜、壳聚糖(质量分数为1%)/柠檬酸(质量分数为1%)复合涂膜处理胡萝卜,以未涂膜处理的胡萝卜为空白对照,研究贮藏期间不同处理组胡萝卜的主要品质指标和生理活性随贮藏时间的变化情况。结果贮藏90 d后,复合涂膜处理组胡萝卜的呼吸强度为3.02 mg/(kg·h),质量损失率为3.32%,Vc含量为0.1704 mg/g,可溶性糖质量分数为2.08%,胡萝卜素含量为0.0549mg/g,POD活性为0.53U/g,PAL活性为65.87U/g,复合涂膜较单一涂膜更好地延缓了贮藏期间Vc含量、可溶性糖含量和胡萝卜素含量的下降,较好地保持了POD和PAL酶的活性。结论壳聚糖涂膜和壳聚糖/柠檬酸复合涂膜处理能够有效提高胡萝卜的贮藏品质,维持其生理活性,延缓衰老进程,其中,壳聚糖/柠檬酸复合涂膜处理的综合保鲜效果要优于单一壳聚糖涂膜处理。

Effects of Chitosan and Citric Acid Composite Film on Preservation of Carrot

This study aims to evaluate the effect of Chitosan and citric acid composite film on the preservation of carrot, and provides a new way for carrot storage after harvest. Carrots were treated with 1% chitosan coating and 1% chitosan/1% citric acid composite coating, with uncoated carrots as control group. The changes in the main quality indicators and physiological activity of different coated carrots over time were analyzed. After 90 days, the respiratory rate of the carrots treated with compound coating was 3.02 mg/(kg.h), the weight loss 3.32 %, the vitamin C content 0.1704 mg/g, the soluble sugar content 2.08%, the carotene content 0.0549 mg/g, the POD activity 0.53 U/g, and the PAL activity 65.87 U/g, and, compared with the single coating, the composite coating delayed the decrease of Vc content, soluble sugar content and carotene content, and maintained the activities of POD and PAL better. Chitosan film and chitosan/citric acid composite film can effectively improve the storage quality of carrots, maintain their physiological activity and delay the senescence process. Also, the carrots treated with composite film have better preservation effects than that treated by single chitosan.