Abstract: Saccharomyces cerevisiae isolated from fresh Raphia palm wine was cultured in Sacoglottis gabonensis (0.625%) treated medium, Alstonia boonei (0.50%) treated medium and untreated medium. Concentrations of plant products used were predetermined as the optimal concentrations of the plant product that had a preservative effect on fermenting palm sap. Flocculation ability, ethanol production, ethanol tolerance, osmotolerance and invertase activity of the yeast isolates in each of the cultures were determined and compared. Alcohol content (6.42%v/v) of untreated sample was significantly lower (p# 0.05) than alcohol content (12.07%v/v) of sample treated with S. gabonensis and A. boonei (11.53% v/v). The two plant products enhanced ethanol tolerance and osmotolerance of the yeast. The flocculation as well as invertase activities of the yeast were however reduced by the two plant products.
O.U Ezeronye , A.I Elijah and P.C. Ojimelukwe , 2005. Effect of Sacoglottis gabonensis and Alstonia boonei on the Fermentation of Fresh Palm Sap by Saccharomyces, Cerevisiae . Journal of Food Technology, 3: 586-591.