茶多酚对壳聚糖/肉桂醛复合膜性能及鱼肉保鲜效果比较

Effects of Tea Polyphenols on Properties and Fish Preservation Performance of Chitosan/Cinnamaldehyde Composite Films

研究了不同茶多酚浓度对美拉德交联壳聚糖/海藻酸二醛-肉桂醛/壳聚糖-茶多酚(CMR/ADA-CA/CS-TP)三层复合膜性能及草鱼保鲜效果的影响。首先制备基于美拉德反应的壳聚糖交联层,随后层层浇铸海藻酸二醛-肉桂醛层和壳聚糖-茶多酚层,最后烘干成膜。当TP升高时,薄膜的颜色加深且透光率降低。薄膜(TP质量分数为0.04%)的拉伸强度升高至31.22 MPa;而薄膜的断裂伸长率则分布在19.59%~22.44%。然而,薄膜的水蒸气和氧气阻隔能力呈现下降的趋势。当TP质量分数为0.08%,薄膜的DPPH自由基清除能力提高至98.12%;培养24 h后金黄色葡萄球菌和大肠埃希氏菌的菌落总数较对照组减少了56.44%和56.29%。贮藏第8天时,活性膜包裹鱼肉的挥发性盐基氮、硫代硫酸巴比妥酸值和菌落总数较对照组分别降低了45.62%、50.70%和2.33 log CFU/g。综合考虑,TP质量分数为0.06%时,膜的整体性能较好,可延长鱼肉货架期,具有作为活性包装对易腐食品保鲜的潜力。

The effects of various concentrations of tea polyphenols on the grass carp(Ctenopharyngodon idella)preservation capabilities of chitosan cross-linked by Maillard reaction/alginate dialdehyde-cinnamaldehyde/chitosan-tea polyphenol(CMR/ADA-CA/CS-TP)trilayer composite films were investigated.The cross-linked CS layer was first prepared using the Maillard reaction.ADA-CA and CS-TP layers were then formed by layer-by-layer casting,followed by drying.With increasing TP concentration,the film color intensified and its transmittance reduced.The tensile strength of film with a TP mass fraction of 0.04%increased to 31.22 MPa,whereas elongation at film break point was 19.59%~22.44%.In contrast,the barrier performances of the film against water vapor and oxygen declined.As the TP mass fraction reached 0.08%,the DPPH scavenging ability of the film increased to 98.12%.Compared with the control,total viable counts of Staphylococcus aureus and Escherichia coli decreased by 56.44%and 56.29%after 24 h of culture.Furthermore,on day 8 of storage,total volatile basic nitrogen,thiobarbituric acid-reactive substances,and total viable counts in fish wrapped with active film decreased by 45.7%,50.7%,and 2.33 log·CFU/g,respectively,compared with the control group.In conclusion,a TP mass fraction of 0.06%yielded the best overall performance of the film.This film additive could prolong the shelf life of fish and offers strong potential to be used as active packaging to preserve perishable food.