METHOD FOR QUICKLY DETERMINING FERMENTATION STAGE AND CHARACTERISTIC AROMA OF SOY SAUCE BASED ON HS-PTR-TOF-MS

The present invention provides a method for quickly determining fermentation stage and characteristic aroma of soy sauce based on HS-PTR-TOF-MS. To detect as many volatile components as possible, a concentration of volatile gas in an upper layer of a headspace is increased by optimizing a plurality of indexes such as headspace sample volume, temperature, time, gas purge flow rate, and salt ion content; HS-PTR-Q-TOF-MS quickly collects statistical analysis mass spectrometry data of a soy sauce sample at different fermentation stages, and constructs a mass spectrometry database for different soy sauce fermentation stages; and a classification and prediction model is constructed by using a plurality of mathematical models such as PCA, PLS-DA, SVM, ANN, RNN, and random forest, and differential mass spectrometry data of different fermentation stages are determined. Compared with the conventional technology, the present invention establishes a novel, accurate and rapid method for collecting and predicting a soy sauce sample in different fermentation processes, and better eliminates the time component caused by personnel interference and long-term instrument analysis.