ABSTRACT:
Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host. The aim of this study was to identify genotypically lactobacilli strains isolated from newborn stools and selecting strain based on probiotic properties (gastrointestinal tolerance, antibiotic susceptibility, inhibition of pathogen biofilm formation, absence of alfa or gamma-blood hemolysis, and lysozyme sensibility) and technological properties of surviving either in ice cream bar or ice-lolly. Reduction of 1.2log cfu ml-1 of the Lactobacillus paracasei strain was observed after exposure through in vitro gastrointestinal conditions. It inhibited biofilms of Escherichia coli, Salmonella Typhimurium and Candida albicans by mechanisms of competition, exclusion and displacement, and was resistant up to 3000μg ml-1 of egg white lysozyme. It presented neither alfa nor gamma-hemolysis or was antibiotic resistant to usual antibiotics for human use. Microbial survivability in ice cream bar or ice-lolly was assessed up to 21 days of storage at -18°C. Viability was maintained in ice cream bar, but there was a reduction of almost 2.0logs in ice-lolly.
Key words:
frozen dessert; functional food; probiotic strain
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), Candida albicans (
), and Escherichia coli (
) biofilm formation by Lactobacillus paracasei DTA 83 by the mechanisms of competition, exclusion and displacement. Biofilm cells were estimated subtracting the biofilm cell counts in co-cultures from the monoculture pathogenic controls after 24h incubation. All reducing mechanisms were significantly different when compared to the control by Dunnett’s test (P>0.05).
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