15C-9 |
Viability of lactobacillus reuteri in buttermilk during manufacturing and storage |
H. S. GARCIA1, B. A. Rodas, and J. O. Angulo. (1) UNIDA, Instituto Tecnologico de Veracruz, M.A. de Quevedo # 2779, Col. FOrmando Hogar, Veracruz, Ver., 91897, Mexico There is a current interest in the use of lactic acid probiotic bacteria from intestinal origin in fermented milks. Probiotics are living microorganisms that provide health benefits to the hosts. Addition of probiotic bacteria is done not only for their beneficial properties, but also because probable sensory aspects that could expand the variety of probiotic formulations. A probiotic product must contain a minimum of 106 CFU/ml during storage; however, it has been reported that pH, acidity and possibly antagonistic effects with the lactic started may affect viability of the probiotic bacteria. Our objective was to prepare a probiotic buttermilk containing * 106 CFU/ml Lactobacillus reuteri and study its viability during storage. The probiotic culture was added either together with the starter (0.5 or 1.0 %) or at the end of the fermentation (1 %). Viability of L. reuteri was monitored by plating on LBS medium, incubated anaerobicaly at 37 °C for 48 h. Acidity, pH and proteolysis were monitored during 16 days of storage. Sensory evaluation of the different buttermilks was performed by a trained panel of 7 judges and using a triangular test to detect differences. Incorporation of 1% probiotic with the starter culture produced viable L. reuteri cell counts of log10 6.77-7.22 CFU/ml after 10 days refrigerated storage. No differences were noted in pH values and acidity after the buttermilk was prepared, and hence no effect on probiotic viability was observed. A limited proteolysis was measured with the mixed culture, which apparently was beneficial for the L. reuteri. Our trained panelists found no differences in the fermented milk attributed to the probiotic. Our results suggest that addition of the probiotic before the fermentation produced viable cells with counts above 106 CFU/ml after 10 days with no adverse effects on the sensory quality of the product.
Session 15C, Dairy Foods
|