distillate was collected, and the ethanol content was determined by density measurement (proof and tralle hydrometer) and corrected to 15.56”C. The standard cooking procedure was as follows.First, the banana feedstock was hand chopped and mashed with a pastry cutter. Water was added at a rate of 0.4 kg water/kg fcsdstock, and 1 g Takatherm/kg feedstock was also added. The mixture was then heated to 93°C for 60 min while being constantly stirred. Next, the mixture was cooled to 60°C and the gluco-amylase enzyme was added at a rate of 1 g Diazymeikg feedstock. The mixture was held at 60°C for 60 min. Finally, the mixture was cooled to 35°C and distiller’s yeast was added at a rate of 1 g yeast0000 ml mixture. Variations in this standard cooking and fermention process wcrc made when the various parameters affecting the ethanol yield wet-c investigated.
The amounts ofThe amounts of enzymes and yeast used were approximately double the optimum amounts recommended by the manufacturer so that any yield reduction would not be due to their limitations. After cooking, the beer was fermented for 72 h at 35°C. In commercial ethanol production, 72 h is about the maximum time used for batch fermentations.This time was used in these studies so that yield reduction would not result from insufficient time for complete fermentation.