壳聚糖复合防腐剂对新鲜猪肉冷藏的保鲜效果

通过检测经防腐保鲜处理新鲜猪肉样和对照样在低温冷藏过程中细菌总数、挥发性盐基氮、色泽和气味等指标随时间的变化,检验壳聚糖和壳聚糖锌复合防腐剂在新鲜猪肉冷藏保鲜中的防腐护色效果。结果表明,新鲜猪肉短时浸泡壳聚糖锌复合防腐剂后,置于无菌环境下于4℃低温冷藏,保存24d都不变质,鲜艳红润的颜色可以保持9d;壳聚糖复合防腐剂处理后,鲜艳红润的颜色可以保持9d,至第15天后样品已经变质;0.5%乙酸处理样品较好的肉色保持9d,至第13天时样品已经变质;而空白对照样在第6天已变暗,品质已改变。壳聚糖锌复合防腐剂用于新鲜猪肉的低温防腐保鲜效果相比壳聚糖防腐剂更好,可将新鲜猪肉的保质期延长7d,比不加防腐剂处理的样品保质期延长3倍以上。

Studies on fresh-keeping effect of complex preservative mostly consisted of chitosan-zn or chitosan to pig meat under low temperature

The antiseptic or retained freshness effect of the complex preservative mostly consisted of chitosan-Zn or chitosan,sodium diacetate and ethyl p-hydroxybenzoate and natamycin were evaluated by measurement four parameters of pig meat kept under low temperature of 4～10 ℃,where the four parameters include the total bacterial counts(TBC),the total volatile basic nitrogen(TVB-N),the tincture and the smell of the meat.The TBC was assayed by methods according to GB 4789.2——2010.the TVB-N of the meat was tested by the standard GB/T 5009.44——2003,the tincture of the kept meats was observed by eyes,the smell sensed by noses.The proportion of the preservatives was also screened by our previous work.The fresh pig meat soaked the complex preservative mostly consisted of chitosan-zn had no peculiar smell,the lower TBC and the lower TVB-N at the 24th day under 4 ℃,but the meat soaked the complex preservative mostly consisted of chitosan had been go bad at the 15th day under 4 ℃,the meat soaked the 0.5% acetic acid liquid had been go bad at the 13th day at the same temperature,all this three samples had brightly moist meat color at the first 9 days under 4 ℃,the worst was the contrast(CK) sample,which had been go bad and with dim meat color at the 6th day under 4 ℃.In a word,the four parameter had relation with quality of the meat,among them,the meat colour was the mostly likely to change.If we made a definition for good quality meat with the lower TBC(here<108 CFU/g or 5×107 CFU/g),the lower TVB-N(here<130 mgN/100 g meat),no peculiar smell and accepted colour,the guarantee period of fresh meat soaked the complex preservative mostly consisted of chitosan-zn was prolonged for a week than the meat soaked the formula mostly of chitosan,and that was three times of the contrast(CK)sample.