Enhancement of Natural GABA Production in Yogurt by Simple Carbohydrates and Metabolomics Profiling During Fermentation of Novel, Self-Cloned Lactobacillus Plantarum Taj-Apis362

Abstract This study aimed to enhance natural GABA production in yogurt by adding glucose (2%, w/v) in the presence of low glutamate concentration (11.5mM vs. reported range of 32–507 mM) without the need of pyridoxal 5’-phosphate (PLP) cofactor, producing GABA at 58.56 mg/100g, significantly surpassing that of PLP (48.01 mg/100g). Simulated gastrointestinal digestion showed a non-significant reduction in GABA content and probiotic viability, demonstrating resistance towards a high acidic environment (pH 1.2). Refrigerated storage up to 28 days revealed an improved GABA production of 83.65 mg/100g compared to fresh GABA-rich yogurt prepared at day 1 (59.00 mg/100g). Metabolomics profiling revealed different metabolite concentrations of amino acid, sugar and organic acid in GABA-rich and standard yogurt. The results successfully mitigate the over-use of glutamate substrate and omit the use of PLP cofactor during GABA enhancement in a fermented food system, offering an economical approach to produce a probiotic-rich dairy food with anti-hypertensive effect which is susceptible to manage stress and prevent cardiovascular disease.