壳聚糖-水飞蓟素复合保鲜涂膜的制备及其在猪肉保鲜中的应用

Preparation of chitosan-silymarin composite coating and its application in pork preservation

为天然复合保鲜涂膜的进一步开发和应用,该文以壳聚糖为成膜基质,以水飞蓟素为主要抑菌剂并以基于壳聚糖质量的0%、2%、4%、6%、8%的添加量制备壳聚糖-水飞蓟素复合保鲜涂膜。通过测定复合保鲜涂膜的DPPH自由基清除率、zeta电位以及流变特性来探究不同水飞蓟素添加量对保鲜涂膜性能表征的影响,同时测定猪肉不同冷藏期间的pH、汁液流失率,挥发性盐基氮(total volatile basic nitrogen,TVB-N)、硫代巴比妥酸(thiobarbituric acid reactive substances,TBARS)、菌落总数以及感官评价来探究不同水飞蓟素添加量对猪肉冷藏保鲜效果的影响。结果表明,随着水飞蓟素添加量的增加,各组保鲜涂膜抗氧化活性显著增加,且zeta电位均大于30 mV,表现出典型的非牛顿剪切变稀流体行为,具有较好的稳定性。其中8%水飞蓟素添加量的保鲜涂膜对猪肉的冷藏保鲜效果的提升最佳,冷藏12 d后,与对照组相比,2%、4%、6%、8%水飞蓟素添加量的保鲜涂膜使猪肉的pH分别降低15.92%、19.39%、21.56%、23.30%,汁液流失率减少19.58%、22.76%、31.33%、39.16%,TBARS降低25.97%,39.75%、58.35%、64.90%,TVB-N降低23.50%、30.56%、47.71%、52.35%。由此可见,壳聚糖-水飞蓟素复合保鲜涂膜可延缓冷藏猪肉品质的劣变,可作为一种优良的可食性涂膜应用于食品保鲜。

For the further development and application of natural composite fresh-keeping coating,chitosan-silymarin composite fresh-keeping coating was prepared with chitosan as film-forming substrate,silymarin as main bacteriostatic agent and 0%,2%,4%,6%and 8%based on the mass of chitosan.The effects of different silymarin addition on the properties of composite fresh-keeping coating were investigated by measuring DPPH radical scavenging rate,zeta potential and rheological properties.At the same time,the pH,juice loss rate and total volatile basic nitrogen(total volatile basic nitrogen,TVB-N),thiobarbituric acid reactive substances(TBARS),the total number of colonies and sensory evaluation to explore the effects of different silymarin addition on pork cold storage.The experimental results showed that with the increase of silymarin content,the antioxidant activity of each group of fresh-keeping coatings increased significantly,and the zeta potential was greater than 30 mV,which showed typical non-Newtonian shear thinning fluid behavior and had good stability.Among them,the preservative coating with 8%silymarin had the best effect on the preservation of pork in cold storage.After 12 days of cold storage,compared with the control group,the preservative coating with 2%,4%,6%,and 8%silymarin reduced the pH of pork by 15.92%,19.39%,21.56%,and 23.30%,respectively,and the juice loss rate decreased by 19.58%、22.76%,31.33%,and 39.16%,TBARS decreased by 25.97%,39.75%,58.35%,and 64.9%,and TVB-N decreased by 23.50%,30.56%,47.71%,and 52.35%.Therefore,chitosan-silymarin composite coating can delay the deterioration of chilled pork quality,and can be used as an excellent edible coating in food preservation.