Mead Production by Saccharomyces cerevisiae Safbrew T-58 and Saccharomyces bayanus (Premier Blanc and Premier Cuvée): Effect of Cowpea (Vigna unguiculata L. Walp) Extract Concentration

This work evaluated the effect of the cowpea ( Vigna unguiculata L. Walp) extract concentration on mead production. Fermentations were carried out in 500-mL Erlenmeyer flasks containing 250 mL of honey wort (30 °Brix), supplemented with 1 g L −1 of ammonium sulfate and 0.1 g L −1 of magnesium chloride and the cowpea extract (5 and 30 g L −1 ), inoculated with 10 6 cells mL −1 , and incubated at 30 °C for 240 h. Higher cell growth ((cells mL −1 ): 11.1 × 10 7 , 11.3 × 10 7 , and 19.6 × 10 7 ; substrate consumption (%): 86.0, 90.0, and 85.0) and ethanol production ((v v −1 %): 15.0, 15.5, and 14.1) for yeasts Safbrew T-58, Premier Blanc, and Premier Cuvée, respectively, were obtained with 30 g L −1 of bean extract. S. bayanus Premier Blanc had the best metabolic activity with lowest glycerol production (8.5 g L −1 ) and highest ethanol volumetric yields (0.51–1.52 h −1 ) after 48 h of fermentation.