Odor profile characterization and variety identification of brown lactobacillus beverage based on untargeted metabolomics

Odor is an important attribute of fermented dairy products and is an important factor in determining consumer acceptance. However, the odor characteristics of brown lactobacillus beverage (BLB) and the differences in odor among different types of these products have rarely been studied. Here, a comprehensive analysis of different types of BLB were performed by SPME–GC–O–MS and SPME–GC×GC–O–MS techniques based on untargeted metabolomics. Compared with SPME–GC–O–MS, SPME–GC×GC–O–MS identified 26 new odor compounds in BLB, indicating that this method is more suitable for odor characterization of BLB. A total of 149 odor compounds were identified from 13 BLBs, of which 40 were odor-active compounds. Ketones , alcohols, acids, aldehydes, and esters accounted for about 80% of the total odor compounds and constituted the basic odor profile of the BLB. In addition to identifying indicator flavor compounds such as furfuryl alcohol , octanoic acid , and β -myrcene, which are responsible for the differences in odor profiles between different BLBs, the reference content ranges in BLBs were precisely quantified. These findings will provide new insights into the species traceability and odor characterization of BLB samples.