STUDY ON DYNAMICS OF MICROFLORA GROWTH IN PROBIOTIC RENNET CHEESE MODELS.

The production of probiotic cheeses is increasing. Probiotics cheeses always need the application of both traditional mesophilic starter cultures and probiotic strains of lactic acid bacteria (LAB). The manufacture of probiotic cheese only with probiotics is not possible because of their weak growth in milk and the lack of proteolytic activity. The aim of this work was to determine the dynamics of growth of LAB in four probiotic rennet cheese matrices depending on ripening temperature (6°C, 10°C, and 14°C for 8 weeks) and probiotic strains used (Lb. casei Defensis DN- 114001, Bif. animalis subsp. lactis Bb-12, Lb. acidophilus La-5). The present work demonstrates that there are probiotic cultures capable to survive in cheese matrices at a level meeting the therapeutic minimum requirements. The number of lactococci was above 7 log CFU/g, aside from ripening temperature. It was not observed an inhibitory effect of probiotic strain on mesophilic starter culture, independently on the probiotic one used. The growth of Lb. casei strain Defensis DN-114001 was better at 14°C than at 6°C, whereas the population number of Bif. animalis subsp. lactis Bb-12 decreased during the ripening of cheese models, aside from the temperature. Probiotic strain Lb. acidophilus La-5 was characterised by much better viability than Bif. animalis subsp. lactis Bb-12. The reduction of pH value has been observed during the maturation of cheese samples. [ABSTRACT FROM AUTHOR]