牛至精油活性膜对黑鱼片的保鲜效果

Preservation effect of active film containing oregano essential oil on snakehead slices

以牛至精油作为抗菌剂,分别加入到乙烯—乙烯醇共聚物(EVOH)和聚乙烯(PE),通过挤出流延制备成2种食品保鲜膜。对保鲜膜的机械性能、透光率和雾度进行表征。用2种保鲜膜包装黑鱼,测定其汁液流失率、pH值、硫代巴比妥酸(TBA)和菌落总数随贮藏时间的变化。结果显示,牛至精油的加入对薄膜的基本性能影响不大;保鲜膜能够减缓所包装黑鱼片的汁液流失率、pH值的增长速度,抑制鱼肉脂质氧化。空白组鱼肉样品的菌落总数在第4天就几乎到达了6lg CFU/g,而含精油的样品组的菌落总数在第8天才接近6lg CFU/g。从菌落总数的变化来看,相对于空白组,含精油的保鲜膜能够减缓包装鱼肉中微生物的生长速度。

In order to study the preservation effect of oregano essential oil in plastic films,oregano essential oil,as an antibacterial agent,was added into ethylene-vinyl alcohol copolymer(EVOH)and polyethylene(PE)respectively,then the food preservative films were prepared by extrusion casting.The mechanical properties,transmittance and haze of the preservative film were characterized.The snakeheads were then packaged in the preservative films,and the changes in drip loss rate,pH,thiobarbituric acid(TBA)and total viable count over time were determined.The results showed that the addition of oregano oil has little effect on the basic properties of the film;the preservative films could slow down the growth rate of drip loss rate and pH of the packaged snakeheads pieces and inhibit the lipid oxidation of fish.The total viable count in the blank group of fish samples in this experiment reached almost 6lg CFU/g on the 4th day,while the total viable count in the sample group containing essential oils was close to 6lg CFU/g on the 8th day.According to the change of the total viable count,relative to the blank group,the preservative films containing essential oil could slow down the growth rate of microorganisms in the packaged fish meat.