UV-C照射与壳聚糖涂膜对鲜切淮山的保鲜效果

Effect of UV-C Irradiation and Chitosan Coating on Preserving the Quality of Fresh-Cut Chinese Yam

对不同贮藏时间的鲜切淮山,采用3.0 kJ/m^2剂量的短波紫外线(short-wave ultraviolet,UV-C)照射和质量浓度10 g/L壳聚糖涂膜处理,研究两种处理方法及二者协同作用对鲜切淮山生理指标的影响,探讨其保鲜效果及保鲜机理。结果表明,与对照组相比,UV-C处理鲜切淮山能够促进酚类物质和类黄酮类物质积累,增强抗氧化能力,抑制氧化损伤。壳聚糖涂膜鲜切淮山,主要通过抑制呼吸作用、降低细胞膜透性、降低细胞膜脂质过氧化而延长保鲜时间。当鲜切淮山贮藏达到12 d时,与对照组相比较,UV-C照射处理、壳聚糖涂膜、二者共同处理使呼吸强度分别降低15.7%、21.3%和23.6%,使菌落总数分别降低24.6%、18.5%和30.8%,使总酚含量分别增加13.3%、16.7%和22.2%,使1,1-二苯基-2-三硝基苯肼自由基清除率分别提高17.5%、9.6%和20.2%。由此可知,3.0 kJ/m^2剂量的UV-C照射与质量浓度10 g/L壳聚糖涂膜对鲜切淮山均具有较好的保鲜效果,二者协同处理的保鲜效果更好,本研究可为鲜切果蔬的保鲜与贮藏提供借鉴。

The influence of short-wave ultraviolet(UV-C)irradiation at a dose of 3.0 kJ/m^2,10 g/L chitosan coating and their combination on physiological indices of fresh-cut Chinese yam at different storage times was investigated in order to explore the effect of these treatments on preserving the quality of fresh-cut Chinese yam and the underlying mechanism.The results showed that compared with the control group,UV-C irradiation could promote the accumulation of phenolics and flavonoids,enhance antioxidant capacity and reduce oxidative damage.Chitosan coating maintained the quality of fresh-cut Chinese yam for a long time by inhibiting respiration,reducing the permeability of the cell membrane,and decreasing lipid peroxidation in the cell membrane.On day 12 of storage,UV-C irradiation,chitosan coating and their combination reduced the respiration intensity by 15.7%,21.3%and 23.6%,reduced the total number of bacterial colonies by 24.6%,18.5%and 30.8%,increased the total phenol content by 13.3%,16.7%and 22.2%,and enhanced the 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging activity by 17.5%,9.6%and 20.2%respectively when compared with the control group.Therefore,both treatments especially their combination was effective in preserving the quality of fresh-cut Chinese yam.This study is meaningful for the preservation of fresh-cut fruits and vegetables.