超声波-离子液体耦合预处理制备蚕蛹蛋白质ACE抑制肽的工艺优化

为提高蚕蛹蛋白质酶解产物的ACE抑制活性,利用超声波-离子液体耦合法对蚕蛹蛋白质进行预处理。以酶解产物ACE抑制活性为指标,采用单因素结合响应面分析法,研究超声波-离子液体耦合预处理蚕蛹蛋白质的工艺条件,并通过SDS-聚丙烯酰胺凝胶电泳,研究预处理前后蚕蛹蛋白质及其酶解产物相对分子质量的变化。结果表明,各因素对酶解产物ACE抑制活性的影响程度由大到小依次为:液料比、超声波功率、预处理时间。确定最佳预处理工艺条件为:液料比27.2 mL/g,处理时间31.9 min,超声波功率406.8 W。在此优化条件下,蚕蛹蛋白质酶解产物的ACE抑制率为75.7%(IC50=0.071 mg/mL)。与未处理、超声波预处理的相比,超声波-离子液体耦合预处理在制备蚕蛹蛋白质ACE抑制肽上具有明显优势。超声波-离子液体耦合预处理后,蚕蛹蛋白质的分子质量无明显变化,但其酶解产物的分子质量(1.43 ku)变小。

Optimization of Preparation Technology of ACE-Inhibitory Peptides from Silkworm Pupae Protein by Coupled Ultrasound-Ionic Liquids Pretreatment

With the aim to improve the ACE-inhibitory activity of hydrolysates from silkworm pupae protein, a pretreatment method of the coupled ultrasound-ionic liquids was used. Taking ACE-inhibitory activity as index, the technology conditions of silkworm pupae protein pretreatment by the coupled ultrasound-ionic liquids were determined with single factor experiments and response surface methodology. In addition, the molecular weight changes of silkworm pupae protein and its hydrolysate after pretreatment were studied by Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE). The results indicated that the effect sequence of three main factors for ACE-inhibitory activity from big to small was as follows: liquid-solid ratio, ultrasonic power, pretreatment time. The optimal pretreatment conditions were as follows: liquid-solid ratio 27.2 mL/g, pretreatment time 31.9 min, ultrasonic power 406.8 W. Under the optimal pretreatment conditions, the average ACE-inhibitory rate of silkworm pupae protein hydrolysate was 75.7% (IC50=0.071 mg/mL). Compared with the un-pretreatment and ultrasound pretreatment, the pretreatment of the coupled ultrasound-ionic liquids has obvious advantages in increasing ACE-inhibitory activity of silkworm pupae protein hydrolysate. After the coupled ultrasound-ionic liquids pretreatment, the molecular weight of silkworm pupae protein has no significant change, while the molecular weight of its hydrolysate(<1.43 ku) becomes smaller.