https://doi.org/10.17113/ftb.64.02.26.9241

Development of Gamma-Aminobutyric Acid (GABA)-Rich and Probiotic-Fermented Soymilk Using Lactiplantibacillus plantarum W12 as a Starter Culture

Nguyen Cao Cuong¹, Bir Bahadur Thapa², Ngoc Hieu Nguyen³, Tran Thanh Quynh Anh¹, Pham Hoang Son Hung⁴, Peter Vandamme⁵ and Do Thi Bich Thuy^6,7*

¹Faculty of Engineering and Food Technology, University of Agriculture and Forestry, Hue University, 102 Phung Hung Street, Thua Thien Hue 530000, Vietnam

²Molecular Biotechnology Laboratory, School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Nakhon Ratchasima 30000, Thailand

³University of Medicine and Pharmacy at Ho Chi Minh City, 217 Hong Bang Street, District 5, Ho Chi Minh City 700000, Vietnam

⁴Faculty of Animal Sciences and Veterinary Medicine, University of Agriculture and Forestry, Hue University, 102 Phung Hung Street, Thua Thien Hue 530000, Vietnam

⁵Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium

⁶Institute of Research and Development, Duy Tan University, 254 Nguyen Van Linh Street, Da Nang 50312, Vietnam

⁷School of Engineering and Technology, Duy Tan University, 254 Nguyen Van Linh Street, Da Nang 50312, Vietnam

Copyright © 2024 This is a Diamond Open Access article published under CC-BY licence. Copyright remains with the authors, who grant third parties the unrestricted right to use, copy, distribute and reproduce the article as long as the original author(s) and source are acknowledged.

Food Technol. Biotechnol. 2026; 64(2) pp. 222-236.

Article history:

Received: 19 June 2025

Accepted: 21 March 2026

Keywords:

gamma-aminobutyric acid; fermented soymilk; Lactiplantibacillus plantarum; response surface methodology; glutamate decarboxylase; functional food

The content of this publication has not been approved by the United Nations and does not reflect the views of the United Nations or its officials or Member States.

Summary:

Research background. Fermented soymilk has emerged as a potential functional food due to its nutritional and health-promoting properties. Enhancing its functionality by enriching it with gamma-aminobutyric acid (GABA), a neurotransmitter with various health benefits, is an area of active research. This study aims to develop a novel GABA-enriched fermented soymilk using a newly isolated Lactiplantibacillus plantarum strain with both probiotic and GABA-producing capabilities.

Experimental approach. Five L. plantarum strains isolated from Vietnamese soybean whey were screened for GABA production and probiotic characteristics. Strain W12, which exhibited superior performance, was selected for optimisation. Response surface methodology with a central composite design was used to optimise monosodium glutamate (MSG) and sucrose amounts for maximal GABA yield. A time-course study was then conducted to monitor bacterial growth, pH changes, organic acid production, and GABA accumulation during fermentation under the optimised conditions.

Results and conclusions. L. plantarum W12 demonstrated exceptional probiotic traits: 97.1 % survival at pH=2.5, 96.5 % survival in bile salts/pancreatin, 97.3 % pepsin tolerance, 96.7 % auto-aggregation and 85.4 % hydrophobicity in chloroform. Initial GABA production reached (9.1±0.4) mM. Response surface optimisation predicted a maximum GABA concentration of 34.2 mM at 1.564 mg/mL MSG and 10.93 % sucrose, which was experimentally validated at (34.5±1.0) mM (15 h, 45 °C). Lactic acid was the predominant organic acid produced ((182.4±8.0) mg/g at 18 h), with viable cell counts exceeding 7.9 log CFU/mL, meeting probiotic thresholds.

Novelty and scientific contribution. This study presents the first comprehensive characterisation of L. plantarum W12, a strain combining exceptional GABA biosynthesis with robust probiotic properties. The systematic response surface methodology (RSM) optimisation framework and detailed metabolic profiling provide reproducible protocols for developing multifunctional fermented soy beverages with applications in neurological and gastrointestinal health promotion.