载银壳聚糖涂布纸对樱桃番茄保鲜包装效果的影响

Fresh Preservation Effect of Silver-carried Chitosan Coated Paper on Cherry Tomato

关键词:  壳聚糖  银  涂布纸  保鲜  樱桃番茄

Key Words:chitosan  silver  coated paper  fresh preservation  cherry tomato

摘要:本研究以壳聚糖(CS)和AgNO3为原料,以NaBH4为还原剂,制备了载银壳聚糖(Ag-CS)涂布液,并用该涂布液涂布纸张,制得Ag-CS涂布纸。利用红外光谱仪（FT-IR）、X射线衍射光谱仪（XRD）、扫描电子显微镜（SEM）和X射线光电子能谱仪（XPS）分析Ag-CS复合物结构、形貌和元素组成,以其涂布纸对樱桃番茄(又称圣女果)进行包装,测定其失重率、可滴定酸和标准抗坏血酸（Vc）含量,与无包装、原纸包装、CS涂布纸包装相比较,考察测定不同包装条件对樱桃番茄品质的影响。结果表明,CS中的—NH₂和—OH首先与Ag+发生配位结合,进而被还原成纳米银和壳聚糖配合物Ag-CS,并使其结晶度下降。SEM分析表明,Ag-CS涂布液在纸张表面形成膜层。通过对比发现,Ag-CS涂布纸包装的樱桃番茄10天后失重率为5.87%,可滴定酸含量下降23.29%,Vc含量下降13.62%。与对照样相比较,Ag-CS涂布纸有利于减少营养物质的流失,从而延长果蔬的常温贮藏期。

Abstract:Silver-carried chitosan(CS) coatings were prepared by using chitosan (CS) and AgNO3 as raw materials and sodium borohydride (NaBH4) as reductant and used to prepared the coated paper. The structure, morphology and elemental composition of Ag-CS complex were analyzed with FT-IR, XRD, SEM and XPS. Cherry tomatoes were packaged with the coated paper. Fresh preservation effect of coated paper was studied. Weight loss rate, titratable acid and Vc content of the cherry tomato at different manner of package were measured. The results showed that at first coordination reactions took place between —NH₂ and —OH containing in CS and Ag+. And then Ag+was reduced to the complexes of nano silver and chitosan, i.e. silver-carried chitosan.The crystallinity of CS decreased obviously. SEM confirmed that the film of silver-carried chitosan coatings was formed on the paper surface.After 10 days, weight loss rate, content decreases of titratable acid and Vc were 5.87%, 23.29% and 13.62%, respectively. Compared with the control samples, Ag-CS coated paper could reduce the loss of nutrients, thus the storage time of fruits and vegetables could be extended.