Abstract:Atmospheric and room temperature plasma(ARTP) and nitrosoguanidine(NTG) mutagenesis techniques were used to treat Yarrowia lipolytica C11. Enzymatic properties of the strain were studied. Four mutant strains A6, A12, A13 and N12 were screened out, and their enzyme activities were 1.007, 1.554, 1.139 U/mL and 1.021 U/mL, respectively, which were 1.41, 2.17,1.59 times and 1.43 times of the original strain. The optimal temperature and pH of the four mutant strains were 50 ℃ and 8.0, respectively. Ethanol could inhibit the activity of lipase, and the optimal substrate was changed from C8 ester to C4 ester. A13 and N12 were inoculated into sour meat fermentation, and the volatile flavor substances were determined by solid phase microextraction combined with gas chromatography-mass spectrometry. The results showed that inoculating mutant strains could improve the sensory quality of sour meat and promote the production of volatile flavor substances such as esters, aldehydes and alcohols. The odor activity value(OAV) of ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, heptanal, nonal, (E,E)-2, 4-decanodienal and 1-octene-3-ol were significantly increased, which gave sour meat rose flavor, mushroom flavor, burnt flavor and fruit flavor.