浸渍冻结对调理草鱼块冻藏过程中品质的影响

本文以质构、pH值、脂肪氧化、蛋白质含量、水分含量、挥发性盐基氮、色泽及感官评价为考察指标,结合冻结曲线,研究浸渍冻结和静止空气冻结对调理草鱼块品质特性的影响。结果表明:采用浸渍冻结和静止空气冻结的调理草鱼块通过最大冰晶生成带的时间分别为3.0 min和19.5 min;冻藏期间浸渍冻结的调理草鱼块的硬度、弹性和咀嚼性、蛋白质含量和水分含量均高于静止空气冻结的,但两种冻结方式的鱼块的均显著性下降;pH值、脂肪氧化值、挥发性盐基氮含量和色泽均低于静止空气冻结的,说明冻藏过程蛋白质逐渐变性,品质变差。感官评价进一步显示两种冻结方式处理的调理草鱼块的组织、风味、外观和口感四方面有不同程度的下降,浸渍冻结的调理草鱼块的感官综合评分均比静止空气冻结的高。结果揭示浸渍冻结比静止空气冻结能够更好的保持冻藏过程调理草鱼块的品质。

The Effects of Immersion Chilling and Freezing on Prepared Grass Carp (Ctenopharyngodon idellus) Fillet Quality during the Freezing Process

In this study, the effects of immersion chilling and freezing (ICF) and static air freezing (SAF) on the quality of prepared grass carp fillets (PGCFs) were examined using texture, pH, lipid oxidation, protein content, water content, total volatile basic nitrogen (TVB-N), color, and sensory evaluation as indices, combined with an examination of the freezing curve. The results indicated that maximum ice crystal formation in PGCFs frozen by ICF and SAF required 3.0 min and 19.5 min, respectively. The hardness, springiness, chewiness, protein content, and water content of PGCFs frozen by both techniques showed significant decreases; however, these variables showed higher values for PGCFs frozen by ICF than for those frozen by SAF. In contrast, pH, lipid oxidation, TVB-N content, and color were lower for PGCFs frozen by ICF than by SAF. These results showed that PGCF proteins denatured and their quality gradually decreased during frozen storage. The results of a sensory evaluation further indicated that the structure, flavor, appearance, and taste of PGCFs frozen by ICF and SAF declined by various degrees. The sensory evaluation scores of PGCFs frozen by ICF were higher than those of PGCFs frozen by SAF. In summary, the quality of PGCFs was better maintained using ICF than SAF during frozen storage.