ACE inhibitory peptides and flavor compounds from Se-enriched Bacillus natto fermented chickpea

Food-derived antihypertensive products offer promising alternatives to traditional medications. This study optimized the production conditions of angiotensin I-converting enzyme (ACE, EC 3.4.15.1) inhibitory peptides in chickpeas fermented by Se-enriched Bacillus natto via liquid fermentation and evaluated their antihypertensive potential through ACE inhibition. Results showed that under the optimized conditions (2% inoculum, 19:1 liquid-to-solid ratio (mL/g), and 40 °C), the ACE inhibition rate reached 80.72%. Selenium content in bacterial cells was (1255.26 ± 3.14) μg/g, with a Se-enriched rate of (73 ± 2%). Analysis by gas chromatography-mass spectrometry (GC-MS) revealed that liquid fermentation generated a wider variety of volatiles compared to solid fermentation, and Se-enriched significantly impacted the composition of primary volatiles ( p < 0.05). Total amino acid content in Bacillus natto liquid-state fermented chickpeas (L-SD1) was 48.63 mg/g (32.141 mg/g essential amino acids), compared to 29.20 mg/g (19.298 mg/g essential amino acids) in Se-enriched liquid-state fermented chickpeas (L-Se-SD1). In solid-state fermented chickpeas, amino acid content was lower, with 15.173 mg/g (7.891 mg/g essential amino acids) in non-enriched (G-SD1) and 13.670 mg/g (7.032 mg/g essential amino acids) in Se-enriched (G-Se-SD1). These findings suggest that Se-enriched chickpea fermentation could be a potent functional food strategy for hypertension management. • Se-treated Bacillus natto optimized chickpea fermentation conditions for Se-enriched. • Volatile components in Se-enriched Bacillus natto chickpeas were analyzed with GC-MS. • Se-enriched increased ACE inhibition and affected the types and levels of volatiles.