Efecto el tratamiento ácido de la crema de levaduras sobre la contaminación bacteriana y la eficiencia de fermentación.

CANSECO A.; CERASUOLO E.; RUÍZ M.; CÁRDENAS G.; GUSILS C.

Tucumán

Jornada; XVIII Reunión Técnica Nacional de la Caña de Azúcar; 2012

Sociedad Argentina de Técnicos de la Caña de Azúcar

Alcoholic fermentation is a biological process in which sugars such as glucose, fructose and sucrose are converted in ethanol and carbon dioxide. The recycling of yeasts and contaminating microorganisms causes reduction of industrial efficiency. In this study, the effect of yeast cream acid treatment on bacterial contamination was studied. It was observed that the bacteria count was significantly reduced depending on contact time with the acid (1 to 2 hours) at the studied pH. In addition, at the end of the fermentation process, yeast viability decreased significantly when the time of contact with acid during the pre-treatment was not sufficient. However, the percentage of viable cells increased with time of contact with the acid at all pH values tested, independently of the presence of contaminating bacteria. No significant differences were detected among fermentation efficiency values with different treatments applied. One hour contact of the yeast cream at pH values between 1.5 and 2.5 during acid pre-treatment was effective enough to reduce contamination by polysaccharide-producing bacteria. Yeast viability and fermentation efficiency were not affected when the process had bacterial contamination values below those recommended in previous literature.