壳寡糖、PVP处理对冷藏水蜜桃的保鲜效果比较

Comparison of Effectiveness between Chitosan Oligosaccharide and PVP in Preserving Juicy Peaches during Refrigerated Storage

利用不同质量浓度的壳寡糖(COS)、聚乙烯吡咯烷酮(PVP)及筛选的两者最优处理进行组合,研究在冷藏((3±1)℃)条件下对‘新白花’水蜜桃涂膜后的保鲜效果。结果表明:经单因素试验对比,0.1g/100mL PVP、2g/100mL COS单一涂膜处理对抑制果实呼吸强度、相对电导率地上升,减缓硬度、可溶性固形物(TSS)含量下降具较好效果,因而选择这两个剂量进行组合处理。综合实验中,2g/100mL COS涂膜的果实在贮藏结束时TSS含量显著高于对照(P<0.05),有效减缓了果实中的糖类物质分解,且该处理对果实中丙二醛(MDA)及多酚氧化酶(PPO)地产生均具有较好地抑制作用;0.1g/100mL PVP处理对果实呼吸强度作用与2g/100mL COS相似,但其他指标均弱于后者;2g/100mL COS+0.1g/100mL PVP处理使果实呼吸强度显著小于对照组(P<0.05),相对电导率、MDA含量上升趋势明显减弱,表明综合涂膜对果实细胞壁、细胞膜的保护效果显著。

The effects of coating with chitosan oligosaccharide （COS） and polyvinylpyrrolidone （PVP） coating as well as combination on the quality of ＂Xinbaihua＂ peach （Prunus persica） stored at （3± 1） ℃ were explored. When used separately, 0.1 g/100 mL PVP and 2 g/100 mL COS were very useful to inhibit the increases in respiration intensity and relative conductivity and retard the decreases in firmness and total soluble solid （TSS） content. Furthermore we evaluated the effectiveness of the combined use of 0.1 g/100 mL PVP and 2 g/100 mL COS to preserve refrigerated peaches. Coating with 2 g/100 mL COS led to a significantly higher TSS level after 25 days of storage than the control （P 〈 0.05）, effectively postponed the decomposition of sugars, and potently inhibited the generation of MDA and PPO, and 0.1 g/100 mL PVP had a similar effect on fruit respiration but exhibited weaker effects on other indicators in comparison to 2 g/100 mL COS. Treatment with 2 g/100 mL COS and 0.1 g/100 mL PVP exerted a more significant inhibitory effect on fruit respiration （P 〈 0.05） than the control and markedly slowed down the upward trend of relative conductivity and MDA content, demonstrating the protective effect of this combined treatment on the cell wall and membrane of peach fruits.