Kluyveromyces lactis and Torulaspora delbrueckii: probiotic characterization, anti-Salmonella effect, and impact on cheese quality

Abstract

Cheese presents remarkable diversity and organoleptic richness favored by microbial communities. Different yeasts have already been reported as contributors to cheese characteristics. In this study we aimed to characterize K. lactis B10 and T. delbrueckii B14 probiotic potential and to evaluate their impact on cheese. Yeasts were subjected to hemolysis, mucin degradation, co-aggregation with pathogens, in vivo survival, and antagonism to salmonellosis. Cheeses were produced with pasteurized milk coagulated using commercial rennet. Cheeses were evaluated for texture profile and sensory acceptance up to 40 days of maturation. Both yeasts presented higher co-aggregation to Salmonella than Saccharomyces boulardii. Although both yeasts satisfactorily survived the passage through the gastrointestinal tract, only K. lactis B10 resulted in high survival rate (90%) of mice against salmonellosis. Cheese produced with yeasts on the surface presented no eyes formation, while yeasts inoculated in the mass increased eyes formation. At 21 days of maturation yeasts inoculated in the mass resulted in lower hardness (1787.91), gumminess (1528.70) and chewiness (1339.63). Taste and purchase intention were higher for the cheese produced with yeasts inoculated in the mass. For all maturation times evaluated, most of the tasters expressed a preference for the cheese produced with yeasts inoculation in the mass.