Molecular mechanism of high pressure shear grinding on Feng-flavour Chinese Baijiu ageing

Abstract

Ultrahigh-pressure homogenization is a powerful technique for accelerating Baijiu ageing. In this study, the molecular mechanism of artificial ageing was thoroughly investigated utilizing foodomics combined with a mass spectrum information optimization program. Various characterizations of compounds in the ageing process were performed through ultra high performance liquid chromatography quadrupole-orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap) based colloid theoretics. High-pressure shear grinding provides a high-pressure and high-temperature environment for Baijiu, accelerating the formation of flavour compounds and the decomposition of odour and harmful substances, thus improving the sensory characteristics of Feng-flavour Baijiu and shortening the ageing time. A total of 2069 substances were identified according to fragment spectra and Bayesian network model-based peak distribution. Molecules with VIP > 1, including 14 esters, 10 acids, 4 ketones, 3 aldehydes, 2 alcohols and 2 phenols, were quantified as potential markers of chemometric analysis. A novel prediction model for Baijiu ageing degree was furnished, and ageing years of Feng-flavour Chinese Baijiu were accurately predicted by factor analysis with KMO 0.784 and a polynomial regression model with r 0.94. The results demonstrated that in 400 bar, fresh distilled Baijiu could reach a natural ageing effect of 6.43 years, which was consistent with the sensory evaluation.

Keywords: Artificial ageing; Colloidal; Feng-flavour Chinese Baijiu; Foodomics; UHPLC-Q-Orbitrap.