The integrated metabolomics and sensory analyses unravel the peculiarities of mountain grassland-based cheese production: The case of Parmigiano Reggiano PDO

Untargeted metabolomics based on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry was combined with sensory analysis to provide new insights into the impact of the feeding system from mountain regions (grassland deriving from permanent meadows) on the chemical fingerprint of Parmigiano Reggiano PDO hard cheese. In the framework of a representative investigation, two different ripening times (12 and 24 months) were also considered. Multivariate statistics allowed discriminating cheese samples from different feeding regimens according to their metabolomics signatures. Interestingly, mountain grassland-based cheese samples were characterized by a more favourable fatty acid profile, recording also feed-derived compounds (such as terpenoids and linoleic acid derivatives) potentially associated with both beneficial effects on human health and sensory properties. According to the sensory analysis, the impact of herbs and grass enhanced the colour and retro-olfactive complexity of Parmigiano Reggiano PDO cheese, with spicy, umami and intense vegetal aromatic notes representing distinctive features.