Isolation and selection of γ-aminobutyric acid producing lactic acid bacteria and application in GABA-enriched tomato juice fermentation

Abstract

Tomatoes (Solanum lycopersicum L.) are nutrient-rich fruits with a high glutamic acid content, making them a suitable source for producing γ-aminobutyric acid (GABA) through the action of lactic acid bacteria (LAB). LAB plays a pivotal role in lactic fermentation, enhancing the taste and nutritional value of food products, often contributing to their health benefits. This study isolated GABA-producing LAB from tomatoes and assessed their potential for producing GABA-enriched fermented tomato juice. The results indicated the isolation of 15 LAB strains from the samples of five different tomatoes. All of these strains demonstrated the capability to produce GABA, with levels ranging from 1.732 to 3.113 mg/mL, as determined using thin-layer chromatography (TLC). Through sequencing, the promising strain TO42, identified as Weissella cibaria, was selected for tomato juice fermentation. Furthermore, GABA-enriched tomato juice was successfully fermented at 15 °Brix for 72 h, resulting in the highest recorded GABA and lactic acid content of 9.185 ± 0.398 mg/mL and 13.05 ± 1.56 g/L, respectively.