Adsorption of Phenolic Compounds and Browning Products in White Wines by Yeasts and Their Cell Walls

Abstract

Dehydrated yeast cells at variable concentrations were used as fining agents to decrease the color of white wines with two different degrees of browning (0.153 and 0.177 au, measured at 420 nm). Both wines showed a linear decrease of browning with increasing yeast concentration. However, in terms of efficiency, the yeasts exhibited a higher color lightening at greater concentrations acting on the darker wine. This suggests a preferential retention of some types of yellow-brown compounds that could increase their concentrations at the higher degree of browning. To confirm the role of yeast cell walls in the retention of browning compounds and to evaluate their potential use as fining agents, they were applied at variable concentrations to a browned wine (0.175 au). The cell walls were found to be the active support for the adsorption of browning compounds, but their efficiency was much lower than that of an equivalent amount of the yeast cells from which they were obtained. Finally, HPLC determinations of low-molecular-weight phenolic compounds showed flavan-3-ol derivatives to be significantly retained by both yeasts and their cell walls.

The potency of Saccharomyces cerevisiae and Lactobacillus plantarum to dissipate organophosphorus pesticides in wheat during fermentation

“…These results evidenced that yeast played an important role in promoting pirimiphos methyl dissipation in wheat dough. Ability of S. cerevisiae cells to adsorb various contaminants from surrounding, whether organic or inorganic, were determined earlier (Razmkhab et al 2002;Goyal et al 2003). This implied possibility for adsorption of pesticide molecules, as well.…”

Effect of alcoholic fermentation in the content of phenolic compounds in cider processing

“…An increased surface provided by interstitial spaces favors the adsorption. The surface of yeast cell in the wine fermentation is higher than 10 m 2 .L -1 of the must and some phenolic acids, flavan-3-ol derivatives procyanidins B2 and B4 (Bonilla et al, 2001), phenolic volatiles (Chassagne et al, 2005), colored products formed from phenolics oxidation or condensation reactions can be adsorbed by yeast during the fermentation (red and white wines) (Razmkhab et al, 2002;Mazauric and Salmon, 2005). Another pathway for phenols, with change in the color of the wine involves the direct condensation of the phenols with the acetaldehyde produced by yeasts in fermented drinks (LopezToledano et al, 2004).…”

Retention of Browning Compounds by Yeasts Involved in the Winemaking of Sherry Type Wines

“…This yeast was used as reference on account of its ability to interact with browning compounds in white wines (Bonilla et al 2001, Razmkhab et al 2002. Figure 2 shows the decrease of different compounds in the solution as a result of their absorption by this yeast after 90 min of contact.…”