探寻复合菌液态发酵米糠制备ACE抑制肽的原料预处理方法,以提高ACE抑制肽产率及产物ACE抑制活性。对米糠原料进行膨化预处理以及除淀粉预处理,以枯草芽孢杆菌1389与黑曲霉AS3.350按2∶1接种为发酵菌株,在接种量10.0%、发酵温度30℃、转速200 r/min发酵条件下,以发酵过程中的pH值、氨基酸态氮、还原糖含量、蛋白酶活性、肽转化率、ACE抑制活性为考察指标。结果表明:最佳原料预处理方法为膨化法,处理条件为米糠水分15.0%、挤压温度140℃、螺杆转速140 r/min。经膨化预处理后,复合菌液态发酵米糠制备ACE抑制肽,肽转化率可达38.86%;ACE抑制活性最高为64.48%,各项指标均好于除淀粉预处理。

The pretreatment of raw materials using composite bacteria liquid fermentation to prepare ACE inhibitory peptides were studied to increase the productivity and ACE inhibitory activity of ACE inhibitory peptides. Rice bran raw materials were pretreated through the extrusion and the addition of starch. The compound strains inoculation ratio of Bacillus subtilis 1389 and Aspergillus niger AS3. 350 was 2∶ 1,inoculum was 10. 0%,fermentation temperature was 30℃,the speed was 200r / min. The pH value,amino acid nitrogen,protease activity,reducing sugar content,peptide conversion rate and ACE inhibitory activity were used as evaluation indexes during fermentation process.The results showed that the best raw material pretreatment was obtained using the extruding method. The processing conditions were as follows: moisture of rice bran was 15. 0%,extruding temperature was 140℃ and screw speed was140r / min. Under this condition,the highest conversion rate was 38. 86% and the highest activity of ACE inhibitory peptides was 64. 48%. All indexes were better than those obtained through the addition of starch pretreatment.