Valorization of Winery Spent Yeast Waste Biomass as a New Source for the Production of β-Glucan

In this paper we report the first isolation of yeast β-glucan from a new source, winery spent yeast biomass and its production with an environmental friendly oriented method. β-Glucan has been isolated from brewery wastes and proposed for various applications in food industry but until now the winery solid wastes have not been treated for this purpose. The aim of this study was dual. Firstly, the exploitation of a completely new and alternative source for yeast β-glucan industrial production, winery yeast waste biomass. Secondly, the utilization of winery yeast waste for the production of added value products as a part of an intergraded and sustainable wine industry, targeted to the protection of the environment. β-Glucan isolation from wine lees was performed in a two-step process, yeast autolysis and alkali extraction with NaOH. Autolysis at 55 °C/pH 5.0/48 h with the use of acetic acid from wine must acetic acid bacteria fermentation for the production of yeast extract was optimum. Most purified fraction of β-glucan from red wine lees (28.95 ± 0.50 %) was received with NaOH 2 M/0.5 h/90 °C/1:5 sample to NaOH concentration and from white wine lees (43.37 ± 0.65 %) with NaOH 0.5 M/1.0 h/90 °C/1:5 sample to NaOH concentration. NaOH waste produced during β-glucan isolation process can be further treated for lignin degradation from wood biomass. Winery yeast waste lees can comprise an innovative way for β-glucan production. Further research in extraction methods, immunoactivity and applications of obtained β-glucan from this source, must be investigated. Also, a deeper research for a new β-glucan with wine polyphenols product for incorporation in functional foods and medicines is proposed.