茶多酚复合衬垫的性能及其对鲜肉的保鲜效果

Properties of composite pad containing tea polyphenols and effects on preserving fresh pork

在羧甲基纤维素钠/壳聚糖/蒙脱土复合衬垫中添加茶多酚(tea polyphenols,TP)制备抗氧化复合衬垫,用做市售冷鲜肉的保鲜包装。研究考察了茶多酚的含量对衬垫的水溶胀率、溶解度、网络结构、抗氧化能力以及对鲜肉保鲜效果的影响。由于茶多酚与羧甲基纤维素钠和壳聚糖间的相互作用,含茶多酚衬垫的网络结构变得更加致密,导致了溶胀率和溶解度的降低。同时,茶多酚的高效抗氧化性使衬垫具有显著的自由基清除能力,且随茶多酚含量的提高而增强。保鲜实验结果表明:在鲜肉的包装托盘中垫上复合衬垫,能有效延缓鲜肉的挥发性盐基氮(total volatile base nitrogen,TVB-N)含量、硫代巴比妥酸反应物(thiobarbituric acid reactive substances,TBARS)含量和菌落总数的增长,延长货架期并改善其外观,尤以茶多酚含量为10%的复合衬垫效果最好。

Tea polyphenols （TP） was added into composite pads which has sodium carboxymethyl cellulose （CMC-Na） , chitosan （CS） and montmorillonite （MMT） to function as antioxidant pads in chilled fresh pork preser- vation. The effects of TP content on swelling ratio, solubility, network structure, compressive strength, color, antioxi- dant activity and preservative effects on chilled fresh pork of composite pads have been investigated. The pad swelling ratio, water solubility, net frame structure and antioxidantive activities were studied. It was found that swelling ratio and water solubility were decreased due the interactions between TP and polymer matrix （ CMC-Na and chitosan）. Moreover, as a powerful antioxidants, TP provides the pads significant free radical scavenging activity, and the effect was content dependent. The preservation experiments showed that the composite pads placing at the bottom of plastic tray, the increasing rates of total volatile base nitrogen （TVB-N） , thiobarbituric acid reactive substances （TBARS） and total bacterial counts were significantly reduced, shelf-life and the appearance of the packaged fresh pork both got improved. Therefore, the antioxidative composite pad developed in this study is environmental friendly, safe and effi- cient. It has great potential in packaging for fresh pork and other foods.