Interaction between commercial mannoproteins and phenolic compounds of two red wines from different Portuguese grape cultivars

A great variability in the amount of polysaccharides recovered at the end of fermentations carried out by pure cultures of 89 non-Saccharomyces yeasts was observed. The utilization of the best polysaccharides producers in mixed cultures with S. cerevisiae resulted in considerable increases in the final concentration of polysaccharides and showed a strain dependent effect on glycerol production as compared to pure culture of S. cerevisiae.

In this study for the first time, eight natural stilbenes (trans-resveratrol, trans-piceid, cis-piceid, trans-astringin, trans-piceatannol, (+)-trans-s-viniferin, pallidol and hopeaphenol) isolated and purified from Vitis vinifera, were simultaneously separated and analysed within 5 mn by ultra high pressure liquid chromatography coupled with photodiode array detection.

The present paper reports the development of an optimized method for simultaneous analysis of
8 biogenic amines (Histamine, Methylamine, Ethylamine, Tyramine, Putrescine, Cadaverine, Phenethylamine, and Isoamylamine). It is based on a method developed by Gomez-Alonso et al. in 2007.

In white wines, Verdejo wine stands out because of its high content in total amino acids. The total content in biogenic amines was low in all wines analyzed and putrescine was the predominant biogenic amine.

The cultivar with a greater oenological potential was ‘Monastel’, which showed overall better values than ‘Tempranillo’ in colour intensity, total polyphenol index, wine colour, total anthocyanins, resveratrol and gallic acid.