Enhancement of Doubanjiang-meju quality by Rotary-drum Fermenter under Unsteady Temperature Field: physicochemical properties, sensory and flavor compounds

In this study, the flavor of the doubanjiang-meju product in the rotary-drum fermenter (PRF) was evaluated by comparing that of the product under the constant temperature (PCT) and the product in the traditional fermentation (PTF). The physicochemical indexes of PRF were optimal, with organic acid content 1.1 and 1.76 times that of PCT and PTF, respectively. A total of 201 flavors were detected in the three products. The flavor content in PRF were 27.24% and 130.72% higher than in PCT and PTF while its aflatoxin B 1 (AFB 1 ) content was the lowest. The colors of PRF were closer to the reddish-brown, and the PRF possessed higher sauce flavor, enduring fragrance, alcohol smell as quantitative descriptive analysis (QDA) shows. A total of four aroma compounds with OAV>1 were identified in the three products. Correlation analysis indicated that the correlations between aromas and other indicators in PRF were the most obvious. These results indicated that the PRF quality was superior to that of PCT and PTF because of the improved mass and heat transfer. The large-scale industrial production might be limited due to the equipment rotation. This study could provide valuable reference to improve the flavor and quality of doubanjiang-meju.