Fermented sheep's milk enriched in gamma-amino butyric acid (GABA) by the addition of lactobacilli strains isolated from different food environments

Lactic acid bacteria, and especially lactobacilli, are the main producers of γ-amino butyric acid (GABA), which has numerous potential health benefits. In this work, the GABA production capacity in milk of 38 native strains of lactobacilli isolated from different food ecosystems was evaluated, and three of them were selected for the production of fermented sheep's milk enriched in GABA without the addition of monosodium glutamate. Physico-chemical analyses (pH, titratable acidity, total solids), including water retention capacity, viscosity, production of GABA, glutamic acid, were carried out, as well as descriptive sensory analysis in fermented milks for a storage period of 28 days at 4 °C. GABA concentrations around 200 mg/L were found in fermented milks made with the strains Lacticaseibacillus paracasei Lb41 and Lactiplantibacillus plantarum Lb56. Furthermore, these fermented milks also presented higher viscosity values than the control, and they had good and typical sensory characteristics.