Optimized submerged cultivation for γ-aminobutyric acid (GABA)-enriched sprouts from brown rice

This study focuses on developing a more efficient cultivation method for sprouted brown rice (SBR), with particular emphasis on enhancing γ-aminobutyric acid (GABA) accumulation. Germinated brown rice has been shown to promote positive effects on human health. Furthermore, its sprouted form, SBR, can accumulate more phytochemicals, particularly GABA. Despite its potential health benefits, SBR faces a lack of optimization and understanding of cultivation practices. To address this, we aimed to optimize the cultivation conditions for SBR through a series of single-factor experiments combined with an orthogonal test. Brown rice grains were submerged in cultivation liquid during a 144-h cultivation process under different conditions. The use of slightly acidic electrolyzed water (SAEW) with an effective microorganism level of 1 mL/L significantly increased the average length, sprouted ratio, and GABA content of SBR. Subsequent investigations and the orthogonal test showed that conditions including 1-day dark treatment, seeding density of 0.150 g/cm 2 , water level of 1.0 cm, and temperature of 32 °C resulted in SBR with both long shoots and high GABA content. Validation samples under the optimized conditions yielded a high GABA content of 243.97 ± 7.18 mg/100 g dry weight and an average length of 37.54 ± 1.32 mm. The submerged cultivation method was shown to efficiently produce high-quality SBR, paving the way for future studies on industrial applications.