Abstract:This study used Bacillus natto with strong selenium-enriched ability as the fermentation strain，chickpea as the raw material，and the angiotensin I converting enzyme（ACE）as indicators. Optimum conditions for the production of ACE inhibitory peptides by Bacillus natto after selenium enrichment were optimized by single-factor experiments and response surface optimization method. Meanwhile，ultra performance liquid chromatography electrospray ionization tandem mass spectrometry（UPLC-ESI-MS/MS）was used for the qualitative and quantitative analysis of seleno-amino acid after selenium enrichment in chickpea. The results showed that L-selenocysteine was the main seleno-amino acid in chickpeas after selenium enrichment.The optimal conditions for the production of ACE inhibitory peptide by Bacillus natto after selenium enrichment were determined：inoculation amount of 2%，liquid material ratio of 18∶1（mL/g），fermentation temperature of 40 ℃.Under these conditions，the ACE inhibition rate could reach 89.24%.The results of the comparative experiments showed that the activity of ACE inhibitory peptide production of chickpea fermented by Bacillus natto without selenium enrichment was 66.35%，indicating that selenium enrichment Bacillus natto fermented chickpeas had a good inhibitory effect on ACE activity.