Abstract: In this study, a reflux stirring fermenter, a pneumatic stirring fermenter and a mechanical stirring fermenter were separately used for mechanized brewing of Zhejiang rosy vinegar after adding water. The yield, organic acid composition, and volatile components of Zhejiang rosy vinegar were determined after the completion of fermentation. The results showed that the yield of Zhejiang rosy vinegar made from 1 kg of rice was increased from 7.84 kg to 8.25 and 8.13 kg by using the pneumatic stirring fermenter and the mechanical stirring fermenter with a stirring frequency of once every five days compared with the traditional fermenter, respectively. The content of lactic acid in rosy vinegar produced using the reflux stirring fermenter was relatively high, and the content of non-volatile organic acid in rosy vinegar was increased by using the pneumatic stirring fermenter. Principal component analysis and cluster analysis showed that different fermenters had a great effect on organic acid composition of Zhejiang rosy vinegar whereas stirring frequency had little effect. The amino acid content increased with the increase in stirring frequency. The amount of volatile components produced by using the reflux stirring fermenter was significantly lower than that obtained using the other fermenters. Principal component analysis and cluster analysis showed that different fermenters had a significant influence on volatile components while stirring frequency had little influence. The quality of the rosy vinegar produced by using the pneumatic stirring fermenter with a stirring frequency of once every five days was the closest to that of traditional rosy vinegar.

Key words: Zhejiang rosy vinegar, organic acids, amino acid, volatile components