Authors : Kingsley C. Egemba and Victor E. Etuk
Abstract: The yeast fermentation of malted sorghum for burukutu has been investigated by following the sugar depletion profile at 20, 25 and 30�C. Fermentations were carried out in a 2L laboratory fermentor at a constant pH of 3.5, while the sugar concentration was determined by the titration method of Lane and Eynon. A test of the Michaelis-Menten model for shifting-order kinetics and a second-order model for fit on the sugar depletion data, showed that while the Michaelis-Menten model failed to describe the mode of sugar consumption, the second-order model gave a good fit of the data for all the fermentation runs. The kinetics of the fermentation of burukutu beer therefore, follow a second-order model. The fermentation rates increased with temperature and were higher for seeding with yeast compared with the practice of using an old brew of burukutu. The rate constant ranged from 0.1070-0.1541 L (cell) 1hr 1 within the temperature range investigated, with activation energy of 71.89 KJ Kmol 1. It would appear that the use of a starter culture of yeast could ensure higher fermentation rates, but the effect of this on the burukutu beer quality would need to be examined.
Kingsley C. Egemba and Victor E. Etuk , 2007. A Kinetic Study of Burukutu Fermentation . Journal of Engineering and Applied Sciences, 2: 1193-1198.