淀粉填充PE膜的制备及保鲜和降解性能的研究

摘  要

具有优良透气性能的可降解保鲜膜是果蔬保鲜包装领域需求越来越大的一种功能性薄膜。本文以低密度聚乙烯（LDPE）为基材，选择淀粉为填充剂，针对改善薄膜的透气性、透湿性和降解性，制备了不同添加量的淀粉PE保鲜膜。根据薄膜的拉伸强度、断裂伸长率、透氧率和透湿量，分析不同添加量的淀粉对薄膜基本性能的影响。利用所制保鲜膜对枇杷进行自发气调包装，通过测定枇杷的失重率和感官评分，研究不同添加量的淀粉填充膜对枇杷保鲜效果的影响。同时进行降解实验，通过测定薄膜的失重率和力学性能的改变，分析不同添加量的淀粉对薄膜降解性能的影响。
结果表明：随着淀粉添加量的增加，薄膜的拉伸强度和断裂伸长率逐渐降低，其透气性和透湿性却有很大的改善。淀粉填充膜对枇杷的保鲜效果优于空白膜和未包装的对照组，其中以填充树脂总量20%的淀粉填充膜包装的枇杷的保鲜效果最好，其包装的枇杷第14天的失重率为5.3%。通过对薄膜失重率和力学性能的测定可知，淀粉的填充提高了薄膜的降解性能，而且随着淀粉添加量的增加，降解性能也逐渐提高。

关键词：LDPE，保鲜，降解，淀粉，枇杷

 
ABSTRACT

Fresh-keeping film which had good gas permeation and degradability was one of the functional films which had more and more calls in the area of fruit’s storage. In this paper, LDPE material was used as a substrate and the fecula as filler to improve the gas and vapor permeation and degradability of film, and many films were prepared with different content of fecula. According to film’s tensile strength, elongation at break, gas permeability and vapor permeability, the effect of fecula on films’ capability was analyzed. The films were used to package loquat for examining fresh-keeping performance. The percentage of losing-weight and organoleptic test were examined which were used to discuss the fresh-keeping performance of the film. The degradation test was going on at the same time, and the percentage of losing-weight and the mechanical capability were tested to discuss the film’s degradability.
Here are the results: as the filler of fecula increased, film’s tensile strength, and elongation at break reduced gradually, but the gas and vapor permeation improved to a large extent. The fecula films performed better than un-packing group in the fresh-keeping test of loquat. The film with 20% fecula showed the best performance, and the loquat’s percentage of losing-weight was 5.3% on the 14th day. With the test of film’s percentage of losing-weight and mechanical capability, it was shown that filling film had good degradability, and the degradation degree of degradable film was more than that of pure PE film.

Keywords: LDPE, fresh-keeping, degrade, fecula, loquat

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