Novel fermented chickpea milk with enhanced level ofγ-aminobutyric acid and neuroprotective effect on PC12 cells

Abstract

In this study, novel fermented chickpea milk with highγ-aminobutyric acid (GABA) content and potential neuroprotective activity was developed. Fermentation starter that can produce GABA was selected from 377 strains of lactic acid bacteria isolated from traditional Chinese fermented foods. Among the screened strains, strain M-6 showed the highest GABA-producing capacity in De Man–Rogosa and Sharp (MRS) broth and chickpea milk. M-6 was identified asLactobacillus plantarumbased on Gram staining, API carbohydrate fermentation pattern testing, and 16s rDNA sequencing. The complete gene encoding glutamate decarboxylase was cloned to confirm the presence of the gene inL. plantarumM-6. The fermentation condition was optimized by response surface methodology. Results demonstrated thatL. plantarumM-6 produced the highest GABA content of 537.23 mg/L. The optimal condition included an inoculum concentration of 7%, presence of 0.2% (m/v) monosodium glutamate and 55 µ M pyridoxal-5-phosphate, incubation temperature of 39 °C and fermentation time of 48 h . GABA-enriched chickpea milk exerted protective effects on PC12 cells against MnCl2-induced injury. GABA-enriched chickpea milk improved cell viability and markedly attenuated the release of lactate dehydrogenase compared with the impaired cells.