A New Chemical Pathway Yielding A-Type Vitisins in Red Wines.
A new chemical pathway yielding A-type vitisins in red wines is proposed herein from the reaction between anthocyanins and oxaloacetic acid (OAA). This new chemical path is thought to occur in the first stages of the wine production even during the fermentation process. This is due to the revealed high reactivity of OAA with anthocyanins compared with the already known precursor (pyruvic acid, PA). In model solutions at wine pH (3.5), when malvidin-3-O-glucoside (mv-3-glc) is in contact with OAA and PA a decrease in the OAA concentration is observed along with the formation of A-type vitisin. Moreover, part of the OAA is also chemically converted into PA in model solutions. The reaction yields were also determined for OAA and PA using different mv-3-glc:organic acid molar ratios (1:0.5, 1:1, 1:5, 1:10; 1:50, and 1:100) and these values were always higher for OAA when compared to PA, even at the lowest molar ratio (1:0.5). The reaction yields were higher at pH 2.6 in comparison to pH 1.5 and 3.5, being less affected at pH 3.5 for OAA. These results support the idea that OAA can be at the origin of A-type vitisins in the first stages of wine production and PA in the subsequent ageing process.
['Araújo|Paula|P|', 'Fernandes|Ana|A|', 'de Freitas|Victor|V|', 'Oliveira|Joana|J|']
D000704:Analysis of Variance D000872:Anthocyanins D002851:Chromatography, High Pressure Liquid D005638:Fruit D005960:Glucosides D006863:Hydrogen-Ion Concentration D053858:Metabolic Networks and Pathways D008956:Models, Chemical D015394:Molecular Structure D062907:Oxaloacetic Acid D019289:Pyruvic Acid D027843:Vitis D014920:Wine
red wines anthocyanins oxaloacetic acid pyruvic acid malvidin-3-O-glucoside carboxypyranomalvidin-3-O-glucoside vitisin