Effects of Co-inoculated Fermentation on Fermentation Aroma of Simulated Grape Juice

To investigate the effect of co-inoculation of Saccharomyces cerevisiae (S. cerevisiae) and Oenococcus oeni on aroma compounds of simulated grape juice, autochthonous Oenococcus oeni strains MG-1, GF-2 and commercial strain VP41 were inoculated respectively during alcoholic fermentation to trigger malolactic fermentation. The volatile aroma compounds in simulated wine samples were determined by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) technique, and the influences of different strain combinations and inoculation time on the fermentation aroma compounds was revealed by multivariate statistical analysis. Results showed that co-inoculum of S. cerevisiae and Oenococcus oeni led to 6.67%-15.56% and 18.75%-40.63% reduction in the contents of volatile acids and residual sugars, respectively (P<0.05), and increased significantly (P<0.05) the type and content of fermentation aromatic substances. Orthogonal partial least squares-discriminant analysis combined with odor active value of aroma substances showed that there were 11 common differential substances between the co-inoculated treatments of different Oenococcus oeni strains, especially in the wine sample of co-inoculated treatment of S. cerevisiae VW inoculated for 48 h followed by Oenococcus oeni MG-1 strain (VM48), contents of ethyl hexanoate, ethyl caprylate, ethyl caprate, isoamyl acetate, phenethyl acetate and 2-phenylethanol were significantly increased by 46.16%-237.41% (P<0.05), and the tropical fruit, red fruit and floral characteristics of wine were more prominent. Results of this study provide a theoretical basis for co-inoculation fermentation of Saccharomyces cerevisiae strains and excellent autochthonous Oenococcus oeni strains in the winemaking process. © 2024 Chinese Institute of Food Science and Technology. All rights reserved.