Comparative analysis of metabolites in cow and goat milk yoghurt using GC-MS based untargeted metabolomics

Overall changes in the metabolite profiles of cow milk yoghurt (CY) and goat milk yoghurt (GY) during 28 days storage at refrigeration temperature were determined. On day 14 of storage, 30 metabolites were significantly different between CY and GY, while days 0 and 28 revealed 13 and 9 significantly different metabolites, respectively. Upregulation (p < 0.05) of free amino acids and dipeptides in GY on day 14 indicated a stronger proteolytic action of bacteria on goat milk proteins, while tri-peptides were upregulated (p < 0.01) in CY revealing its better texture. The predominance of medium-chain fatty acids in GY resulted in the upregulation (p < 0.05) of carboxylic acids and fatty acid derivatives on day 14. In addition, intercellular signaling molecules were upregulated indicating the regulation of pH change in GY during storage. Pathway impact analysis showed the association of differentially abundant metabolites of GY with metabolic pathways of amino-acids. (c) 2021 Elsevier Ltd. All rights reserved.