Investigating the possibility of producing GABA in yogurt using Lactobacillus brevis

Gamma aminobutyric acid (GABA) is a bioactive molecule with various physiological functions in the body that by inhibiting neuronal stimulation and the Prevent of delivery messages containing stressful compounds cause relaxation and has an effective role in the treatment of various diseases. Therefore, the aim of this study was to investigate the effect of two independent variables including pH (4-4.6), glutamic acid (300-600 ppm) on survival and GABA production by Lactobacillus brevis and general acceptance of yogurt. According to the results, with increasing pH and glutamic acid, the survival of probiotic bacteria, the amount of produced GABA and general acceptance significantly (p≤0.05) increased. Simultaneous optimization results (viability of Lactobacillus brevis, GABA content and general acceptance) showed the maximum survival rate (7.7278 log cfu/g), GABA content (342.9444 ppm) and general acceptability score (4.8367) after 28 days of storage, with 98.406% desirability in probiotic yogurt inoculated with Lactobacillus brevis containing 600 ppm glutamic acid and pH 4.60 was observed. The results showed that by using GABA producing probiotic bacteria in yogurt formulation, probiotic yogurt can be produced with desirable nutritional properties and take a positive step towards producing functional products and promoting consumer health.