Stabilization and preservation of probiotic properties of the traditional starter of African opaque sorghum beers

Abstract

This present study assessed the impact of drying process parameters, that is temperature and drying duration, on the dry matter content, pH, titratable acidity, yeasts and lactic acid bacteria content of granule starter of African opaque sorghum beer. Probiotic properties of the dry starter were tested. The aim was to establish levels of temperature and duration of drying that lead to a longer shelf life and optimum activity of the starter. Results show that the drying temperature has significant effects on the titratable acidity, yeasts and lactic acid bacteria contents of the granule starter while the level of dry matter was significantly affected by both temperature and duration of drying. The optimal drying conditions providing a stable granule starter with optimum viability of lactic acid bacteria and yeasts were established to 43°C and 24 h. Both wet and dried starters showed inhibitory effect on the meticillin resistant Staphylococcus aureus.

Keywords: sorghum, opaque beer, starter, yeats, probiotic, Response Surface Methodology