New insights into nonenzymatic browning of non‐PDO Italian hard cheese through a metabolomics approach.

Nonenzymatic browning poses a severe problem to the dairy industry, causing economic losses. In this work, an untargeted metabolomics approach based on ultra‐high‐performance liquid chromatography coupled with Orbitrap mass spectrometry was used to investigate the discoloration found on the inner parts of nonprotected designation of origin Italian hard cheese. Alkyl‐pyrazines, imidazo‐quinoxalines and β‐carbolines were the best markers, suggesting the involvement of microbial methylglyoxal in modulating the browning defect. A better understanding of the microbial composition of natural whey starter could be of interest in future studies to better elucidate the biochemical mechanisms involved and to help generate discriminant metabolites. [ABSTRACT FROM AUTHOR]