不同干燥方式对鲢鱼肉品质变化的影响

Effect of different drying processes on quality changes of silver carp(Hypophthalmichthys molitrix)

以鲢鱼为对象,研究了不同干燥方式对鲢鱼肉脂肪氧化、蛋白质降解和微观结构变化的影响。结果表明,冷风干燥可以较好地防止微生物腐败、抑制内源酶活性,但对鱼肉脂肪氧化的影响较大,酸价和TBA在冷风干燥终点分别增加了141.2%和175.9%;热风干燥促进了鱼肉蛋白的降解和热变性,TCA-溶解肽在热风干燥终点增加了63.1%,说明内源酶和微生物生长促进了蛋白降解,盐不溶性蛋白在热风干燥终点增加了531.0%,说明蛋白质发生了变性聚集;微观结构分析发现,冷风和双阶段干燥可以使鱼肉保持致密的结构,热风干燥后肌纤维会发生严重变形。因此,双阶段干燥综合了冷风和热风干燥的优点,缩短了干燥时间,经过双阶段干燥的鱼肉脂肪氧化程度低,组织结构完整致密。

In this study,silver carp was chosen as the subject.Effects on lipid oxidation,protein degradation and microstructure changes of fish fillets during different drying processes were studied.Results showed that cold-air drying could prevent microbial corruption and inhibit endogenous enzyme activity,but it had a great effect on lipid oxidation with acid value and the content of thiobarbituric acid rising by 141.2% and 175.9% respectively at the end of drying.Degradation and thermal denaturation of fish protein were promoted by hot-air drying with the content of TCA soluble peptide increasing by 63.1% which indicated that endogenous enzymes and microbial growth advanced protein degradation.Meanwhile,the content of salt insoluble protein soared by 531.0% at the end of drying, which meant denaturation and aggregation of proteins occured. Microstructure analysis found that dense structure of fish fillets was kept during cold-air drying and two-stage drying while the muscle fibers were seriously deformed after hot-air drying. Therefore, two-stage drying combined the advantages of cold-air and hot-air drying and shortened the drying time. Fish fillets now had low degree of lipid oxidation and compact structure after two-stage drying.