臭鳜鱼的质构特性、特征气味及发酵微生物的分离鉴定

臭鳜鱼是徽式风味名菜的代表菜品,具有徽菜"轻度腐败、盐重好色"的典型特点。为探究徽菜臭鳜鱼发酵过程的关键影响因素,比较分析臭鳜鱼的鱼肉质构特性和氨基酸成分,确定臭鳜鱼挥发性特征气味的组分,分离和鉴定鳜鱼发酵过程中的关键微生物,结果表明:发酵8 d的鳜鱼鱼肉无明显鱼腥味,有淡臭味,臭鳜鱼的鱼肉硬度为3000.37 N,为新鲜鱼肉的2.72倍,粗蛋白和粗脂肪含量分别为19.2%和10.54%,必需氨基酸组氨酸(3.44%)和甲硫氨酸(5.01%)分别为新鲜鱼肉的4.32倍和3.09倍;通过DHS-GC-MS技术测定臭鳜鱼挥发性特征气味的主要成分为丙酸和异丙胺,丙酸和异丙胺分别占总气体成分的20.91%和41.17%,具有强烈臭味的丙酸是形成鳜鱼臭味的主要组成成分;筛选鳜鱼发酵微生物,根据微生物的细胞形态、生理生化指标,采用16S rDNA技术进行分子鉴定以及进化树分析,鳜鱼发酵主要微生物为蜡样芽孢杆菌和苏云金芽孢杆菌。

Texture Properties, Characteristic Smell, Microbial Isolation and Identification of Smelly Mandarin Fish

Smelly Mandarin fish is a representative flavor dish of Anhui. The traditional food possesses the representative characteristic of Anhui cuisine, such as mild rot, high concentration salt and bright color. To explore the key influence factors during fermentation for smelly Mandarin fish, the determination of texture properties and amino acids ingredients, distinction of characteristic smell components and identification of the key microorganism species during fermentation were carried out. The results showed that Mandarin fish reached optimum quality through eight days fermentation. The processed meat exhibited light smell without the fishlike smell. And the hardness of the processed meat was 3000.37 N, 1.72-fold higher than that of the fresh one. The content of crude protein and crude fat were 19.2% and 10.54%, respectively. Both histidine (3.44%) and methionine (5.01%) were 3.32-fold and 2.09-fold higher compared with those of the fresh. The volatile components of smelly Mandarin fish were mainly composed of 41.17% isopropyl amine and 20.91% propionic acid by DHS-GC-MS, and the major composition of characteristic smell was defined by propionic acid. Using the techniques of cell morphology, physiology, biochemistry, 16S rDNA molecular identification and evolutionary tree analysis, the microorganisms related to the fermentation of Mandarin fish were mainly Bacillus cereus and Bacillus thuringiensis.