Vitamins in grape must: let’s lift a corner of the veil

Abstract

Although vitamins stand as major actors to yeasts prime metabolic pathways, their significance in oenology and winemaking remains rather obscure nowadays, having been mostly unexplored for several decades. While those investigations allowed for a primary estimation of the vitaminic contents of musts and wines, no quantification of their vitameric distribution has ever been performed. Here, in order to elucidate a still-obscure facet of wine composition, 19 different vitamers from 8 different vitaminic groups (B1, B2, B3, B5, B6, B8, B9, C) have been simultaneously and directly analyzed by an optimized rapid HPLC procedure in 85 white grape musts from different geographical origins, varieties, as well as vintages. This novel insight on must composition reflects the overall must diversity, since their vitameric contents vary highly between musts. Plus, this investigation provided leads for characterization of the matrix, since, notably, distinctive patterns could be observed in regards to the musts area of cultivation. Such an analytical tool allows for a precise estimation of the must contents in the different water-soluble vitamers, to provide with a
refined management of winemaking and avoid significant deficiencies that could occur during fermentation, or as a result of winemaking practices. As such, the impact held by some oenological practices on vitamins has also been investigated, and proved to have no significant effect. Overall, this offers ground for further determination of the vitamin significance in oenology, and provide a new tool for alcoholic fermentation management.