外源NO联合壳聚糖/纳米TiO2涂膜复合处理对枇杷保鲜效果的影响

Effects of Exogenous NO Combined with Chitosan/Nano-TiO2 Coating on Preservation of Loquat Fruit

目的研究外源NO联合壳聚糖/纳米TiO2涂膜处理对采后枇杷品质的影响,以期获得协同增效的枇杷保鲜方式。方法以蒙自“大叶子”枇杷为实验材料,分别采用蒸馏水(对照)、硝普钠(SNP,外源NO供体)处理、壳聚糖/纳米TiO2涂膜处理、外源NO联合壳聚糖/纳米TiO2涂膜处理观察枇杷在(4±1)℃下贮藏75 d过程中的品质变化。结果适宜浓度的外源NO(cSNP为0.05 mmol/L)能有效减缓采后冷藏枇杷果实的木质化进程,减少冷害的发生;适宜浓度的壳聚糖/纳米TiO2复合涂膜液(TiO2 c纳米为0.5 g/L)能有效抑制枇杷表面微生物的增长,降低呼吸强度和腐烂率;复合处理(外源NO+壳聚糖/纳米TiO2)更为有效地降低了枇杷果实储存期间的菌落总数,减少了贮藏过程中水分的散失,有效地减缓了木质化败坏进程,更有利于枇杷的保鲜。结论相比于单一的外源NO或壳聚糖/纳米TiO2涂膜处理,外源NO联合壳聚糖/纳米TiO2涂膜处理对枇杷的保鲜效果更好。

The work aims to get a synergistic method of keeping loquat fresh by studying the effects of exogenous NO combined with chitosan/nano-TiO2 coating on quality of postharvest loquat fruit.The“large-leaf”loquat fruit from Mengzi was used as the experiment material and treated with distilled water(control),sodium nitroprusside(SNP,exogenous NO donor),chitosan/nano-TiO2 and exogenous NO combined with chitosan/nano-TiO2,respectively.The quality changes of loquat fruit were observed during storage for 75 d at(4±1)℃.The appropriate concentration of exogenous NO(cSNP of 0.05 mmol/L)could effectively slow down the lignification process of postharvest frozen fruits and reduce the occurrence of cold damage.The appropriate concentration of chitosan/nano-TiO2 coating solution(cnano-TiO2 of 0.5 g/L)could effectively inhibit the growth of microorganisms on Loquatfruit surface and reduce the respiratory intensity and decay rate.However,compound treatment(exogenous NO+chitosan/nano-TiO2)was more conducive to the preservation of loquat fruits,which reduced the total number of colonies during storage,decreased the loss of water during storage,and effectively slowed down the process of lignification deterioration.Compared with single exogenous NO or chitosan/nano-TiO2 coating treatment,exogenous NO combined with chitosan/nano-TiO2 coating treatment has better preservation effect on loquatfruit.