复合保鲜剂协同超高压对鲈鱼贮藏品质的影响

为了提高鲈鱼贮藏期间的品质,以4℃冷藏鲈鱼为对照,采用超高压技术(200 MPa,5 min)结合2种不同的复合保鲜剂(0.15%壳聚糖+0.50%ε-聚赖氨酸、0.15%壳聚糖+1.50%ε-聚赖氨酸)保鲜鲈鱼,以菌落总数、理化指标(挥发性盐基氮TVB-N、pH、色度、剪切力)为评价指标,测定鲈鱼在4℃冷藏12 d内的保鲜效果。结果表明:冷藏鲈鱼货架期为6 d,单独超高压组的冷藏鲈鱼货架期为9 d,超高压结合复合保鲜剂后可将冷藏鲈鱼货架期延长至12 d,经过复合保鲜剂处理的超高压各组,在12 d时,其剪切力显著高于单独使用超高压组和冷藏对照组(p <0.05),且菌落总数TVC、挥发性盐基氮TVB-N、pH和白度均显著低于单独使用超高压组和冷藏对照组(p <0.05)。其中0.15%壳聚糖与1.50%ε-聚赖氨酸复配后保鲜效果最佳,能明显抑制鲈鱼冷藏过程中的菌落总数,减缓蛋白质分解,有效地保持了冷藏鲈鱼的品质。

Effect of Compound Preservatives with Ultra-high Pressure on Storage Quality of the Largemouth bass

In order to improve the quality characteristics of the Largemouth bass during storage,the Largemouth bass was refrigerated at 4 ℃ as the control,ultra - high pressure technology (200 MPa,5 min) combined two different composite preservatives(0.15% chitosan + 0.50% ε-polylysine,0.15% chitosan + 1.5% ε-polylysine)to pretreat Largemouth bass.To evaluate the preservation effects of Largemouth bass during 12 d at 4 ℃,total bacteria count,physical and chemical indicators (total volatile basic nitrogen,pH,color,shear)were periodically analyzed.The results showed that the shelf life of the controls was 6 d,the shelf life of Largemouth bass pretreated by UHP was 9 d,the shelf life of Largemouth bass by UHP combined with preservatives was 12 d.The shearing force of the ultra-high-pressure group treated by composite preservative was significantly higher than the ultra-high-pressure group and the cold control group alone at 12 d(p<0.05),and the total bacteria count, TVB-N,pH and color of samples pretreated by compound preservatives and UHP which both were significantly lower than those of other two groups(p<0.05).Among them,the preservation effects of the samples dipped in 0.15% chitosan +1.50% ε -polylysine had the best preservation effects,which could suppress the growth of spoilage microorganisms effectively,slowd down the decomposition of protein and maintained the good quality of Largemouth bass effectively.