CONICET | Buscador de Institutos y Recursos Humanos

Functional properties of two Lactobacillus plantarum strains (Lp 813 and Lp 998) were evaluated (in vitro)before and after heat adaptation and shock. The stress conditions were selected considering a previouswork: 55 C e 15 min (heat shock) and 45 C e 30 min (thermal adaptation), both performed in MRSbroth. The functional properties evaluated were: a-survival to simulated gastrointestinal tract (GIT:saliva þ bovine pepsina solution brought to pH 2.3 in 90 min, bile solution 1% w/v pH 8e10 min andbile þ pancreatin solution pH 8e30 min), b-co-aggregation with Saccharomyces cerevisiae to simulateintestinal epithelia adhesion, c- auto- and co-aggregation with enteric pathogens (Escherichia coli andSalmonella enteritidis) and d-use of prebiotic compounds (inulin, soluble corn fiber, lactulose and raffinose)evaluated for kinetics of growth. Heat treatments (generally) affected the studied functionalproperties as follows: a-diminished the resistance to acidic step and improved survival undergoing bilepancreatinstep in GIT simulation, b-mean values of auto-aggregation and co-aggregation with yeast orpathogens were not significantly modified, despite an increase in variability and c-prebiotic usediminished in the case of strains subjected tothermal treatments except for raffinose, which showed tohave been better employed in this last case. These results could be very useful when it comes to theselection of microorganisms to be used and conserved in processes and methodologies that involve hightemperatures as a stress factor (spray drying or cheese elaboration).