关键词: 发酵牛肉干；理化特性；氨基酸；脂肪酸；挥发性风味物质

Abstract: Fermented beef jerky was made by inoculating and fermenting beef rump with a mixture of Staphylococcus xylosus and Lactobacillus sake. The nutritional components, texture properties, color, free amino acids, fatty acids and volatile flavor compounds of meat samples at the beginning, middle and end of fermentation were determined. Compared with unfermented beef, the pH, water activity, residual nitrite, hardness and chewiness of fermented beef significantly decreased (P < 0.05), while redness value and the contents of free amino acids increased significantly, with umami amino acids accounting for the highest proportion of the total amino acids. Palmitic acid, stearic acid, oleic acid and linoleic acid were the major free fatty acids, oleic acid accounting for the largest proportion of the total fatty acids. Totally 47 volatile compounds were detected in fermented meat, and 42 in the unfermented sample. Fermentation increased the types and relative contents of aldehydes, alcohols, phenols, esters, acids, nitrogen and other compounds in beef jerky. In conclusion, the texture and color of fermented beef jerky were significantly improved, the contents of free amino acids and fatty acids were increased, and the nutritional value, flavor quality and safety of the product were improved in comparison with unfermented beef jerk.

Key words: fermented beef jerky; physiochemical properties; amino acids; fatty acids; volatile flavor substances