风干武昌鱼的营养及挥发性成分

Nutritional Compositions and Volatile Compounds in Air-Dried Fermented Megalobrama amblycephala

为研究风干武昌鱼的营养价值和特征风味,分析其灰分、脂肪、蛋白质、多肽含量、游离氨基酸和游离脂肪酸组成及挥发性成分。结果显示,风干武昌鱼中蛋白质和多肽含量高达32.72%、4.26%,脂肪和灰分含量分别为9.40%、9.38%。游离氨基酸含量为0.12%,包括人体必需的8种氨基酸,且赖氨酸、蛋氨酸含量分别为总游离氨基酸的3.31%和1.26%;呈味氨基酸(天冬氨酸、谷氨酸、甘氨酸、丙氨酸、丝氨酸、脯氨酸)含量为总游离氨基酸的85.64%,鲜味氨基酸(天冬氨酸、谷氨酸、甘氨酸、丙氨酸)含量高达51.07%。游离脂肪酸中不饱和脂肪酸含量为68.80%,以C18∶1含量最高;多不饱和脂肪酸含量为21.98%,其中C20∶5和C22∶6含量分别为0.40%、0.89%。此外,从风干武昌鱼中检测到奇数碳脂肪酸,例如十五碳脂肪酸和十七碳脂肪酸。挥发性成分中醇类、醛类物质相对含量分别达16.65%、10.91%。说明风干武昌鱼营养丰富,呈味氨基酸和不饱和脂肪酸及挥发性成分含量较高,有利于风干武昌鱼特征风味的形成。

The nutritional components including ash, fat, protein, oligopeptide, free amino acid composition, free fatty acid composition and the volatile compounds were investigated to evaluate the nutritional value and characteristic flavor of air-dried fermented blunt snout bream（Megalobrama amblycephala）. The results showed that the contents of protein, oligopeptide, fat, ash, and free amino acids were 32.72%, 4.26%, 9.40%, 9.38%, and 0.12% in air-dried fermented M. amblycephala, respectively. The fermented fish contained all the essential amino acids, and the contents of lysine and methionine accounted for 3.31% and 1.26% of the total free amino acids, respectively. Moreover, flavor amino acids（aspartic acid, glutamic acid, glycine, alanine, serine and proline） and umami amino acids（aspartic acid, glutamic acid, glycine and alanine） constituted 85.64% and 51.07% of the total free amino acids, respectively. Unsaturated fatty acids（USFA） accounted for 68.80% of the total free fatty acids with C18：1 being the most abundant USFA. The total content of polyunsaturated fatty acids was 21.98%, including C20：5（eicosapentaenoic acid, EPA） and C22：6（docosahexaenoic acid, DHA） accounting for 0.40% and 0.89%, respectively. In addition, odd-carbon fatty acids（pentadecanoic acid and heptadecanoic acid） were also detected in air-dried fermented M. amblycephala. The fermented fish was rich in volatile compounds, and the contents of aldehydes and alcohols were 16.65% and 10.91%, respectively. These results indicated that air-dried fermented M. amblycephala had excellent nutritional composition including high contents of flavor amino acids, unsaturated fatty acids and volatile compounds, which are all conducive to the formation of its characteristic flavor.