Optimisation of fermentation conditions for the production of gamma-aminobutyric acid (GABA)-rich soy sauce

• DOI: 10.1016/j.heliyon.2024.e33147
• Publication Date: 2024-06-18T17:41:59Z
• Authors: Chong Shin Yee; Zul Ilham; Acga Cheng; Muhamad Hafiz Abd...; Siti Hajar-Azhari; Mohd Hafis Yuswan; Nurul Aqilah Mohd...; Anna Reale; Tiziana Di Renzo; Wan Abd Al Qadr I...
• Keywords: Starter; Aspergillus oryzae; Umami; Gamma-Aminobutyric Acid; Reducing sugar

This study addresses the challenge of enhancing gamma-aminobutyric acid (GABA) content in soy sauce through optimized fermentation condition. Using a multiple starter culture, consisting Aspergillus oryzae strain NSK, Bacillus cereus KBC and Tetragenococcus halophilus KBC, incubation conditions including percentage bacterial inoculum (10, 15 20 %), pH (3, 5 7) agitation speed (100, 150 200 rpm) were Response Surface Methodology (RSM). Under optimal (20 % inoculum, 7 stirring at 100 rpm), culture generated 128.69 mg/L GABA after days produced 239.08 4 weeks fermentation, which is 36 higher than under non-optimized (153.48 mg/L). Furthermore, sensory analysis revealed high consumer acceptance fermented control (soy without any treatment additional bacteria) commercial sauce. Consumers indicated that offered an improved umami taste reduced bitter, sour salty flavours compared to product. determined by RSM statistical analysis, able produce levels more likely be accepted consumers. The findings this research have potential impact food sector offering functional with added health benefits also being well-received