Physicochemical and molecular transformation of novel functional peptides from Baijiu.

A novel strategy for screening and identifying peptides present in Baijiu was developed based on magnetic solid-phase extraction with magnetic S-doped graphene (M-G-S) as adsorbent combined with ultrahigh-performance liquid chromatography with high resolution tandem mass spectrometry. In total, 28 peptides consisting of amino acids from 3 to 9 were preliminarily identified, and significantly higher in the number than that of direct concentration and SPE with C as the adsorbent. Six peptides were confirmed with their corresponding synthetic reference standards by comparing their retention time, high resolution MS/MS spectra, and NMR spectroscopic studies.