Gamma aminobutyric acid (GABA) production using Lactobacillus sp. Makhdzir Naser‐1 (GQ451633) in the cherry‐kefir beverage

The aim of this study was to produce gamma aminobutyric acid (GABA) in a probiotic cherry-kefir drink. First, the kefir drink was made from fresh milk utilizing kefir grains, then in the next step, it was fermented using Lactobacillus sp. Makhdzir Naser-1 (GQ451633) to produce GABA. The effective variables considered were: pH, temperature, glutamic acid concentration, incubation time, and cherry juice concentration. To achieve optimum conditions for the GABA production, the design of experiments software was used. After analyzing the results, the optimal conditions specified by the model were: temperature = 36°C, cherry juice concentration (wt.%) = 13, glutamic acid concentration (mM) = 360, time (h) = 38.7, pH 4.4. The GABA production under optimum situations with three repetitions was 3.818 (mg/ml), which differed only by 0.005 from the predicted value of the model. This indicated the high accuracy of the proposed model. Practical applications The production of beneficial foods containing GABA has been significantly considered by researchers due to its important biological and functional properties such as lowering blood pressure, soothing, anti-stress, preventing diabetic conditions, etc. But adding synthetic GABA from chemical methods to food is unhealthy and unnatural; therefore, the biosynthetic pathway of GABA production must be used for food utilization. Kefir (a dairy fermented beverage) has long been traditionally produced and consumed among the people of the world, especially in Asia. This drink is rich in minerals, vitamins, and beneficial microorganisms for the digestive system and body. In this study, along with the addition of fruit juice and natural production of GABA, a useful kefir drink has been produced that is very valuable and nutritious; therefore, it is expected that the valuable place of such foods in the household food basket will increase.