Open AccessMonitoring a Biotechnological Process in a Biofermentor to Obtain a Dairy Product Using Brewer’s Yeasts
Author(s) -
Adriana Păucean,
Dan Cristian Vodnar,
Elena Mudura,
Mirela Jimborean,
Carmen Socaciu,
Dorina Bratfalean
Publication year - 2010
Publication title -
bulletin of university of agricultural sciences and veterinary medicine cluj-napoca. agriculture
Language(s) - English
Resource type - Journals
eISSN - 1843-5386
pISSN - 1843-5246
DOI - 10.15835/buasvmcn-agr:5149
Subject(s) - fermentation , yeast , kefir , food science , lactococcus lactis , microorganism , population , saccharomyces cerevisiae , biology , mixed acid fermentation , lactic acid , bacteria , lactic acid fermentation , microbiology and biotechnology , biochemistry , genetics , demography , sociology
Dairy products may go beyond the borders of nutritional value and become functional products if the fermentation process is performed in the best available manner. Our study monitories the process parameters and their variation during the fermentation time of milk incubated with a complex mixture of microorganisms formed by: a lactic culture, kefir-yeast culture and brewer’s yeasts sampled from the secondary fermentation of beer. The study was realized using a Tryton- Pierre Guerin Technologies biofermentor. The results were correlated with the development dynamics of lactic bacteria and yeasts population during 24 hr of fermentation. The pH level variation is typical for kefir-like products. The oxygen content during fermentation is a competitive factor for the two species of microorganisms featuring in our research: Lactococcus lactis and Saccharomyces cerevisiae. In this situation the semi-anaerobic environment insures the fastest rate of acidification for milk and the Saccharomyces cerevisiae yeasts did not display a fermentation metabolism but maintain their viability.