Influence de la feuille de Hemizygia bracteosa (Benth) sur la qualité de la bière du sorgho "tchakpalo" produite au Bénin

Abstract

This study aims to value the traditional manufacturing process of "tchakpalo" produced with sorghum (Sorghum bicolor (L) Moench) and its stabilization by H. bracteosa (Benth) sheet. A survey was conducted to identify the different manufacturing processes of tchakpalo in Benin. Major chemical groups characterizing the H. bracteosa (Benth) leaves were identified by technique using suitable solvents. The antifungal properties of aqueous extract of H. bracteosa (Benth) leaves were evaluated by the agar diffusion method against strains responsible of the rapid spoilage of the drink. Tannins, the cathechic tannins, flavonoids, anthocyanins, leucoanthocyanes, saponins and mucilage are the predominant compounds of H. bracteosa (Benth) leaves. Antifungal activities of this plant varied depending on the test mold. The addition of the powder during the pasting showed its effect on physico-chemical parameters providing a slightly sweet drink, less acidic, with low alcohol content and makes stable drink with 64% inhibition on total aerobic mesophilic bacteria, 100% and 61% inhibition on mold and coliforms respectively, counted in the drink. In addition, the Hemizygia bracteosa (Benth) powder seems to have no effect on beneficial yeasts for fermentation that were eliminated by pasteurization.