大菱鲆复合生物保鲜剂的优化及保鲜效果研究

为了延长大菱鲆的货架期,选取乳酸链球菌素(Nisin)、乳酸钠和海藻酸钠进行单因素试验,利用响应面Box-Behnken试验设计对复合生物保鲜剂进行复配优化,建立以第9天的鱼肉挥发性盐基氮(TVB-N)含量为响应值的二次多项式回归模型,并通过测定大菱鲆肌肉菌落总数、pH值、TVB-N含量、巯基含量、持水力,以及用低场核磁技术测定水分迁移和光学显微镜观测肌肉组织结构变化,验证最优配比复合保鲜剂的保鲜效果。结果表明,经方差分析和回归拟合,得到3种生物保鲜剂的最佳添加量为Nisin 0.04%、乳酸钠5.92%、海藻酸钠1.06%,经保存9 d的大菱鲆TVB-N有最小值(18.37 mg·100g^-1), 且Nisin与乳酸钠对大菱鲆的保鲜具有显著的交互作用(P<0.05),响应面模型与实际情况拟合较好。经复合保鲜剂处理过的4℃冷藏大菱鲆,货架期可延长至14 d。本研究为制备高品质水产品可食性涂膜提供了理论依据和技术支持。

Optimization of Composite Biological Preservative and Freshness-Keeping Effect for Turbot (Scophthalmus maximus)

To prolong the shelf life of turbot, Nisin, sodium lactate and sodium alginate were selected for single factor experiments. The compounded biological preservatives were optimized through response surface Box-Behnken experiment design. A quadratic polynomial regression model was established using the total volatile basis nitrogen of turbot which had been cold stored for 9 days as evaluation index. And the preservation effect of the optimal proportion compounded biological preservatives was verified by determining the indexes including of aerobic bacterial count, pH value, TVB-N, sulfhydryl content, water-holding capacity, water transport and muscle structure. Through variance analysis and regression fitting, the results showed that the optimal amount of composite biological preservative was composed of 0.04% nisin, 5.92% sodium lactate and 1.06% sodium alginate, and The TVB-N of turbot cold stored for 9 days had a minimum value of 18.37 mg·100g^-1. Moreover, Nisin and sodium lactate had significant interaction on the preservation of turbot (p <0.05) and the response surface model was well fitted with the actual situation. The shelf life of turbot treated with the chosen composite biological preservatives at 4℃ could be prolonged to 14 days. This study provided a theoretical basis and technical support for using edible coatings to obtain high quality aquatic products.