📄 Abstract
ST25 rice (Oryza sativa) is globally celebrated for its premium quality and signature pandan-like aroma, yet its potential for functional food conversion remains underutilized. Enriching ST25 rice with γ-aminobutyric acid (GABA)—a health-promoting neurotransmitter—via microbial fermentation offers a high-value pathway for functional foods, but traditional optimization requires extensive trial-and-error that can degrade flavor and aroma. To solve this, we applied an efficient Gaussian Process Bayesian Optimization (GP-BO) framework to optimize submerged fermentation using Lactobacillus brevis (VTCC 12248). Key factors—inoculum size, initial pH, and fermentation time—were systematically refined across just 15 targeted runs in three sequential rounds. The model identified peak fermentation parameters at a 5.25% v/v inoculum, an initial pH of 5.35, and an incubation time of 38.0 hours. Experimental validation under these conditions produced 6.48±0.18 mg/g of GABA per gram of dry substrate, matching model predictions with a low 0.61% relative error while achieving high probiotic cell counts (9.47\log_{10}{\text{CFU/mL}}) and an 88.42% precursor conversion rate. Sensory evaluation by 30 consumer panelists confirmed that controlled fermentation preserved ST25's natural aroma while significantly enhancing overall taste acceptability from 6.85 to 7.60 on a 9-point Hedonic scale p < 0.001). Compared to conventional Response Surface Methodology, the GP-BO approach reduced experimental time and material costs by over 60%, offering a streamlined blueprint for transforming regional cereal crops into functional food ingredients.
🏷️ Keywords
📚 How to Cite:
Manh Tuan NGUYEN, Kien Minh LA , OPTIMIZATION OF FERMENTATION PARAMETERS AND SENSORY QUALITY FOR HIGH Γ-AMINOBUTYRIC ACID (GABA) ENRICHMENT IN VIETNAMESE ST25 RICE SUBSTRATE USING BAYESIAN OPTIMIZATION , Volume 14 , Issue 10, October 2026, EPRA International Journal of Agriculture and Rural Economic Research (ARER) , Pages: 5 - 12 , DOI: https://doi.org/10.36713/epra31825