Abstract:In order to study the effect of yeast extract on the flavor of soybean yogurt，fresh cow milk and soybean milk were used as raw materials，sugar and yeast extract（FA37，FA39）were added，and soybean yogurt was fermented by strain.The study used gas chromatography-mass spectrometry combined with electronic nose technology and sensory evaluation to analyze soy yogurt with yeast extracts FA37 and FA39，and compared it with soy yogurt without yeast extract（original flavor）.The results showed the presence of a total of 18 volatile flavor substances in soybean yogurt，mainly ketone aldehydes and esters，of which the relative content of beany flavor components was 22.83%.In soybean yogurt with added yeast extracts FA37 and FA39，the volatile flavor substances increased and the relative content of beany flavor components decreased.The results of electronic nose analysis showed that the different systems of soybean yogurt with different types of yeast extracts added were well differentiated and had differences in the overall flavor.Sensory evaluation results showed that adding yeast extracts has a good effect on improving the flavor of soy yogurt.