Fermented Milk Product Enriched with γ-PGA, Peptides and GABA by Novel Co-Fermentation with Bacillus subtilis and Lactiplantibacillus plantarum

Milk was co-fermented with Bacillus subtilis HA and Lactiplantibacillus plantarum EJ2014 to produce a dairy ingredient enriched poly-γ-glutamic acid (γ-PGA) γ-aminobutyric (GABA). The first fermentation of milk B. resulted in viscous broth pH 6.56, 0.26% acidity, 1.40 mg/g tyrosine equivalent, 17.21 U/g protease activity. viable cell counts indicated 8.74 log CFU/mL, the consistency index alkaline fermented 1.82 Pa·sn. In addition, 4.65% mucilage produced 35.93% γ-PGA content. by L. 1.34% acidity 4.91. bacterial decreased 4.44 whereas those increased 9.42 CFU/mL. Monosodium glutamate (MSG) as precursor effectively converted into subtilis, then residual MSG completely GABA yield 26.15 mg/g. Furthermore, volatiles, including hexanoic acid, 2,3-butanediol, acetoin, which may be responsible for its aged cheese-like aroma.