Foods (Oct 2020)

Protection of Wine from Protein Haze Using <i>Schizosaccharomyces japonicus</i> Polysaccharides

  • Valentina Millarini,
  • Simone Ignesti,
  • Sara Cappelli,
  • Giovanni Ferraro,
  • Alessandra Adessi,
  • Bruno Zanoni,
  • Emiliano Fratini,
  • Paola Domizio

DOI
https://doi.org/10.3390/foods9101407
Journal volume & issue
Vol. 9, no. 10
p. 1407

Abstract

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Nowadays commercial preparations of yeast polysaccharides (PSs), in particular mannoproteins, are widely used for wine colloidal and tartrate salt stabilization. In this context, the industry has developed different processes for the isolation and purification of PSs from the cell wall of Saccharomyces cerevisiae. This yeast releases limited amounts of mannoproteins in the growth medium, thus making their direct isolation from the culture broth not economically feasible. On the contrary, Schizosaccharomyces japonicus, a non-Saccharomyces yeast isolated from wine, releases significant amounts of PSs during the alcoholic fermentation. In the present work, PSs released by Sch. japonicus were recovered from the growth medium by ultrafiltration and their impact on the wine colloidal stability was evaluated. Interestingly, these PSs contribute positively to the wine protein stability. The visible haziness of the heat-treated wine decreases as the concentration of added PSs increases. Gel electrophoresis results of the haze and of the supernatant after the heat stability test are consistent with the turbidity measurements. Moreover, particle size distributions of the heat-treated wines, as obtained by Dynamic Light Scattering (DLS), show a reduction in the average dimension of the protein aggregates as the concentration of added PSs increases.

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