Abstract
In this work, a retrospective screening based on ultra-high-performance liquid chromatography (UHPLC) coupled with high-resolution mass spectrometry (HRMS) based on Orbitrap-Q-Exactive Focus™ was used to check the occurrence of regulated and emerging mycotoxins in bulk milk samples. Milk samples were collected from dairy farms in which corn silage was the main ingredient of the feeding system. The 45 bulk milk samples were previously analyzed for a detailed untargeted metabolomic profiling and classified into five clusters according to the corn silage contamination profile, namely: (1) low levels of Aspergillus- and Penicillium-mycotoxins; (2) low levels of fumonisins and other Fusarium-mycotoxins; (3) high levels of Aspergillus-mycotoxins; (4) high levels of non-regulated Fusarium-mycotoxins; (5) high levels of fumonisins and their metabolites. Multivariate statistics based on both unsupervised and supervised analyses were used to evaluate the significant fold-change variations of the main groups of mycotoxins detected when comparing milk samples from clusters 3, 4, and 5 (high contamination levels of the corn silages) with cluster 1 and 2 (low contamination levels of the corn silages). Overall, 14 compounds showed a significant prediction ability, with antibiotic Y (VIP score = 2.579), bikaverin (VIP score = 1.975) and fumonisin B2 (VIP score = 1.846) being the best markers. The k-means clustering combined with supervised statistics showed two discriminant groups of milk samples, thus revealing a hierarchically higher impact of the whole feeding system (rather than the only corn silages) together with other factors of variability on the final mycotoxin contamination profile. Among the discriminant metabolites we found some Fusarium mycotoxins, together with the tetrapeptide tentoxin (an Alternaria toxin), the α-zearalenol (a catabolite of zearalenone), mycophenolic acid and apicidin. These preliminary findings provide new insights into the potential role of UHPLC-HRMS to evaluate the contamination profile and the safety of raw milk to produce hard cheese.
Highlights
Milk is an important constituent of the human diet in the Western world [1]
From a qualitative point of view, the corn silages revealed a similar mycotoxin contamination profile, which was mainly associated with Aspergillus toxins, Penicillium toxins, fumonisins and their metabolites, together with other Fusarium toxins
Our previous work [16] demonstrated that there was a clear impact of contaminated corn silages on the milk metabolomic profiles, and this was true for the metabolism of purines, pyrimidines, sphingolipids, and oxidative stress-related compounds
Summary
Milk is an important constituent of the human diet in the Western world [1]. In recent decades, world milk production has increased by over 60%, from 522 million tonnes in 1987 to 843 million tonnes in 2018 [1]. As recently reviewed [2,3], the spectrum of milk metabolites can be deeply influenced by several external factors, such as the season, origin, health status, processing, storage, formulation, and feeding systems. In this regard, one of the major concerns when considering the feeding system is related to the potential contamination of silages (such as corn silage) by mycotoxins [4,5]. The great ingestion by dairy cows of regulated mycotoxins has been related to the quality of the feeding systems [9]; this aspect remains insufficiently investigated
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
