Metabolic capacity of probiotic mixed cultures formed by Lactobacillus and Bifidobacterium strains for use in functional fermented dairy foods

Abstract

The metabolic capacity of probiotic mixed cultures formed by Lactobacillus and Bifidobacterium strains was assessed through the determination of the acidification profile and the production of amino acids and volatile compounds, during the fermentation of ultra-pasteurized skim milk. Two mixed cultures formed by [L. acidophilus + B. bifidum] and [L. acidophilus + B. animalis] stood out in the production of essential amino acids: His, Ile, Leu, Met, Thr, Trp and Val. As well as increased production of volatile compounds such as: acetoin, 2-heptanone, 2-nonanone, acetic acid, acid butanoic and hexanoic acid, in contrast to commercial fermented dairy products. Additionally, these bacterial mixed cultures were characterized by the production of distinctive volatile compounds: 1-heptanol, diisobutylcarninol, hemellitol, 1-dodecanol, acetone, 2-pentanone, 2-undecanone, ethyl acetate, benzaldehyde as well as valeric, acetyl valeric and isopropylpyruvic acids. Finally, the culture formed by [L. acidophilus + B. bifidum] presented a good acidification profile with a lactic acid production of 26.1 ± 0.1 g / L and pH 3.6 at the end of fermentation. This data suggests a great potential of these mixed cultures to improve the nutritional value and organoleptic characteristics of fermented dairy products, when added as starter or adjunct cultures in the fermentation process.

Effect of microencapsulated Lactobacillus reuteri under simulated gastric conditions and its inhibition on Listeria monocytogenes

“…monocytogenes. The number of peptides and amino acids product of the fermentative bacterial process can be altered by variations in the compounds of proteolytic metabolism, where the type of nutritional needs, intracellular peptidases, and their regulatory mechanisms influence the release to the environment and whose quantitative and qualitative profile have an effect on the characteristics of fermented dairy products (Rosales-Bravo et al, 2020). Some of the important peptide compounds produced by LAB are bacteriocins, thanks to their antimicrobial activity to inhibit the growth of pathogenic microorganisms (Zhao et al, 2020).…”