Insights into flavor quality and metabolites profiles of fresh cheese with different probiotics by SPME-GC-MS and untargeted metabolomics.

In this study, fresh cheeses produced with four novel probiotics (Lactobacillus casei PB-LC39, Lactobacillus rhamnosus PB-LR76, Lactobacillus helveticus HH-LH17, and Lactobacillus plantarum HH-LP56) were named as LC, LR, LH, and LP, respectively. SPME-GC-MS and untargeted metabolomics were used to compare and analyze the flavor quality, metabolites and metabolic pathways of LC, LR, LH and LP, and the potential function of differential metabolites was emphasized. The results demonstrated that the incorporation of probiotics resulted in a significant increase in the number of volatile flavor compounds and varying flavor profiles within the cheese. Especially LC, exhibited aromas reminiscent of wine, fruit and rose, and displayed the most favorable flavor qualities among all probiotic cheeses. The results of differential metabolite screening and metabolic pathway demonstrated that probiotic cheese could result in the production of 146-192 differential metabolites, mainly carbohydrates, proteins and acids. Arginine biosynthesis was a key differential metabolite pathway made by probiotics. The LC, LR, LH, and LP groups contained 22, 27, 23, and 24 functional metabolites, including L-carnitine, naringenin, and turanose et al., which might confer anti-inflammatory and improve lipid metabolism functions. These findings provide a theoretical basis for the further functional evaluation and development of probiotic cheese.