Effect of Asystasia Gangeticum (Atu ukwara) Leaves Extract on Fermentation Kinetics of Elaeis Guineensis (Palm wine)

The kinetic studies of Elais guineensis sap is of major important in determining the extent of preservation of palm wine, since production is highest in the rainy season. The effect of 0.1, 0.2, 0.4, 0.8 and 1.6% Asystasia gangeticum leaves extract (in order to inhibit the activities of microbes during fermentation of E. guineensis sap) on the rate of palm wine fermentation, using 100 mL portion of fresh palm sap was determined. The rate of fermentation is measured as the rate of carbon dioxide production and the equivalent moles of ethanol produced. The results showed that the fermentation rate decreases as the
concentration of A. gangeticum leaves extract increases. Doses of 0.1 and 0.2 % of A. gangeticum leaves extract did not inhibit bacterial activity appreciably, suggesting that at this concentration, bacterial inhibition was not achieved. The results obtained with the sap dosed with 0.4, 0.8 and 1.6 % of A. gangeticum leaves extract suggested that inhibition increases with increase in concentration. Elaeis sap dosed with 1.6 % A. gangeticum leaves extract produce a better effect on palm wine fermentation. In this regard, sap dosed with 1.6 % and higher concentration will offer the most promising way of preserving
palm wine by bottling. However, the percent alcohol decreases lineally as the concentration of A. gangeticum leaves extract increases. Methanol as fermentation product was absent, so the sap and the dosed saps are not methanol toxic. While isopropanol as one of the fermentation products, was present in both the pure and dosed wine.