Abstract:In the present study, bovine legs were selected as the raw material, and the mixed bacteria of Pediococcus pentosaceus and Pediococcus lactis were used as the starter based on the pre-experimental screening, and the fermentation process of conditioned steak was optimized by the response surface method. Using the unfermented conditioned beef steak marinated at low temperature for 10.00 h as the control group, the effects of different treatments on the pH value, texture, color, and flavor of the steak were investigated, and the sensory quality of steak was evaluated using a fuzzy comprehensive evaluation method. The results showed that the optimal process conditions of mildly-fermented conditioned steak were 0.015% fermentation dose, 10.00 h fermentation time, and 31.5 ℃ fermentation temperature. Compared with the unfermented condi- tioned steak, the pH value, hardness and chewiness of the mildly-fermented conditioned steak were significantly reduced (P<0.05), and the values of L*, a*, and b* as well as the sensory score significantly increased (P<0.05). After fermentation, the types of esters, aldehydes, ketones, olefins, and other compounds in the mildly-fermented conditioned steak increased by 0.4%, 3.0%, 0.7%, 0.5%, and 0.7%, respectively. In summary, mild-fermentation may improve the tenderness and flavor of steak, enhance product quality, and provide a theoretical basis for the innovative research on tenderization and provide a theoretical basis for the innovative research on the tenderization of steak and fermented steak products.