响应面试验优化酶法制备辣木籽多肽工艺及其抑菌活性分析

Optimization of Enzymatic Hydrolysis of Moringa oleifera Seed Protein by Response Surface Methodology and the Antibacterial Activity of Peptides of Protein Hydrolysate

摘要:

以辣木籽蛋白粉为原料，首先筛选蛋白水解效果较佳的蛋白酶，其次考察酶添加量（酶底质量百分比）、料液比、酶解温度及酶解时间对蛋白水解度和肽得率的影响，并结合响应面法优化辣木籽多肽制备工艺，最后研究该酶解产物的抑菌活性。实验结果表明，碱性蛋白酶具有较好的蛋白水解度，酶法制备辣木籽多肽的最佳工艺条件为碱性蛋白酶添加量5.50%、pH 9.0、料液比1:30（g/mL）、酶解温度62.50 ℃、酶解时间143 min，在此条件下肽得率实际值为（84.43±2.31）%、蛋白水解度为（20.69±0.46）%。该辣木籽蛋白酶解产物对单增李斯特菌、大肠杆菌、金黄色葡萄球菌、鼠伤寒沙门氏菌等4种致病菌株均有抑制作用，最小抑菌浓度依次为3.00 mg/mL、0.75 mg/mL、0.38 mg/mL、0.75 mg/mL，对培养至4.5 h后的金黄色葡萄球菌呈现较好抑制效果。

Abstract:

Moringa oleifera seed protein powder was used as raw material to prepare for peptides by enzymatic hydrolysis. Firstly, the protease with better proteolysis effect was screened as the optimal enzyme. Secondly, the effects of enzyme addition amount (enzyme-substrate mass percentage), material-liquid ratio, hydrolysis temperature and hydrolysis time on the degree of hydrolysis (DH) and peptide yield were investigated. The process for enzymatic preparation of Moringa oleifera seed peptides was optimized by response surface methodology (RSM). Finally, the antibacterial activity of the hydrolysates was evaluated. Results showed that alkaline protease was the optimal enzyme. The optimal process for enzymatic preparation of Moringa oleifera seed peptides was founded to be alkaline protease addition of 5.50%, pH of 9.0, solid-liquid ratio of 1:30 (g/mL), hydrolysis temperature of 62.50 ℃ and hydrolysis time of 143 min. Under these conditions, the actual peptide yield was (84.43±2.31)%, and the degree of hydrolysis was (20.69±0.46)%. The hydrolysates had inhibitory effects on Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella typhimurium, and the minimum inhibitory concentrations against these above four pathogens were 3.00 mg/mL, 0.75 mg/mL, 0.38 mg/mL and 0.75 mg/mL, respectively. The hydrolysates had better inhibitory effects on Staphylococcus aureus after incubation for 4.5 h.