茶多酚复合可食性涂膜在香梨保鲜中的应用

本论文研究了库尔勒香梨经过涂膜后的保鲜效果。通过单因素实验分析了可食性涂膜中茶多酚、羧甲基纤维素钠(CMC)、甘油的添加量以及淀粉的种类和含量对香梨失重率的影响,并应用响应面试验对其进行了优化;将香梨涂膜后在30℃干燥45 min,分别在10、20、30 d测其硬度、可溶性固形物、可滴定酸、多酚氧化酶的活性。研究结果表明:30℃贮藏30 d,在100 mL去离子水中加入玉米淀粉5 g时,甘油的添加量是1 g,茶多酚的添加量是3 g,CMC的添加量是0.3 g,涂膜保鲜剂处理的库尔勒香梨失重率为4.33%±0.2%。在贮藏实验中香梨随着贮藏时间的延长,涂膜组比未涂膜组的香梨硬度、可滴定酸含量下降要缓慢,但涂膜组与未涂膜组在可溶性固形物、多酚氧化酶活性的测定实验中数值都呈现上升趋势,涂膜组比未涂膜组上升缓慢。涂膜组在30 d内果实表面完好,而未涂膜组在20 d就已发生腐烂变质。由此说明茶多酚复合可食性膜对香梨有较好的保鲜效果,能有效延长香梨的保鲜期。

Application of the Tea Polyphenols Composite Edible Membrane in Preservation of Pear

In this paper,the preservation effect of Korla pear after coating was studied. The effects of the addition of tea polyphenols and CMC,glycerol and the content and kinds of starch in edible composite membrane on the weight loss rate of pear were analyzed by single factor experiments. The tea polyphenols and CMC addition in edible membrane were studied by response surface experiment. The storage experiments were also carried out,and the hardness,soluble solids,titratable acids,and polyphenol oxidase activities of fragrant pears were tested by drying them in a drying oven at 30℃ for 45 min. The results showed that after 30 d of storage at 30℃,when corn starch of 5 g was added to 100 mL deionized water,the addition amount of glycerin was 1 g and that of tea polyphenols was 3 g,the added amount of CMC was 0.3 g,the weight loss rate of korla pear treated with coating preservative was 4.33%±0.2%。In the storage experiment,the hardness and titratable acid contents of the pear in the coated group decreased more slowly than that in the uncoated group with the prolonged storage time,but the values in the coated group and the uncoated group showed an increasing trend in the determination of soluble solids and polyphenol oxidase activity,while the values in the coated group increased more slowly than those in the uncoated group. The fruits of the coated group were intact within 30 d,while those of the uncoated group were rotten and deteriorated within 20 d. So that the tea polyphenols composite edible membrane would have a good effect on the preservation of pear,and it could effectively prolong the freshness of pear.