Viability of probiotic bacteria during manufacture and ripening of a semi-hard Argentinean cheese

BERGAMINI, CARINA V.; MERCANTI, DIEGO J.; HYNES, ERICA R.; QUIBERONI, ANDREA; SUÁREZ, VIVIANA B.; ZALAZAR, CARLOS A.

San Miguel de Tucumán, Tucumán, Argentina

Simposio; Simposio Internacional de Biotecnología. Aplicaciones en Alimentos, Salud y Medio Ambiente. II Simposio Argentino-Italiano de Bacterias Lácticas.; 2004

Centro de Referencia para Lactobacilos (CERELA) y la Planta de Procesos Industriales Microbiológicos (PROIMI), con el aval del (CONICET), la Agencia Nacional de Promoción Científica y Tecnológica y la Agregaduría Científica de la Embajada de Italia

Two strains of probiotic bacteria, one of Lactobacillus acidophilus and the other of Lactobacillus paracasei subsp. paracasei, were tested as adjunct cultures in cheese-making experiments, in order to assess their viability during cheese-making and ripening. The adjunct culture was added to cheese-making milk following two different methodologies: as a lyophilized powder dispersed in milk, or within a milk-milk fat substrate. An increase in lactobacilli population and a consistent reduction in pH value were observed during the incubation of the substrate inoculated with either L. acidophilus or L. paracasei subsp. paracasei. In all cheeses, probiotic bacteria increased a log cycle during cheese-making, and remained almost constant during ripening (60 days), always in higher number than the required to meet probiotic standards. Losses of probiotic bacteria in whey were negligible. Gross composition of the cheeses was not affected by the addition of probiotic bacteria, except for pH value: cheeses with L. acidophilus added within the pre-incubated substrate, had lower pH values and were over acidified and crumbly. Direct addition of the probiotic culture was the methodology with the best performance; however the pre-incubation presented some advantages as an increased population of lactobacilli in the initial inoculum.