Research on the Process and Quality of Rosy Vinegar Production by Multi-strain Mixed Cranking
To investigate the impact of multi-strain koji production on the process and quality of Zhejiang Rose Vinegar,a study was conducted to optimize the multi-strain ratio using an orthogonal experiment.The two best-performing mixed strains were applied to the production of rose vinegar,and a quality evaluation was performed.The results indicated that two ratios with the highest amylase and protease activities were 1∶1∶1∶1 and 1∶1∶1∶2 of Monascus purpureus∶Aspergillus oryzae∶A.niger∶Rhizopus,which were prepared and subsequently applied to the vinegar brewing process.Fermentation tracking showed that the multi-strain fermentation process for rose vinegar was successfully completed,with the total acidity of the final products reaching 6.97 g/100 mL and 6.63 g/100 mL,respectively,representing a yield increase of 17.21%and 11.29%compared to the traditional method.Eight flavor-contributing organic acids,including acetic acid,lactic acid,malic acid,and citric acid,were detected in the two rose vinegar samples,with non-volatile acid contents of 56.04 mg/L and 57.85 mg/L,respectively,which were comparable to the 41.053 mg/L of traditional rose vinegar.A to-tal of 44 volatile flavor compounds were identified using headspace solid-phase microextraction combined with gas chro-matography-mass spectrometry(HS-SPME-GC-MS),with volatile flavor compound contents of 6 348.14 mg/L and 6 791.75 mg/L in the two groups,slightly higher than the 5 030.07 mg/L in traditional vinegar.Sensory evaluation revealed that rose vinegar brewed with multi-strain koji showed slight improvements in sweetness and ester aroma,with the 1∶1∶1∶2 multi-strain group achieving the highest sensory scores.This study provides a reference for the mechanized improve-ment of koji production in traditional rose vinegar manufacturing.