黑豆抗氧化肽的酶解条件优化及分级制备

以黑豆分离蛋白为原料,利用Alcalase对其进行酶解制备黑豆抗氧化肽,研究加酶量、底物质量分数、酶解温度和酶解时间对酶解产物抗氧化性和水解度的影响,通过单因素试验和正交试验确定最优酶解条件。采用不同截留相对分子质量的超滤膜对最优酶解条件下制备的黑豆分离蛋白酶解产物进行超滤分离并测定不同组分的抗氧化性。结果表明:制备黑豆抗氧化肽的最优酶解条件为加酶量3%、底物质量分数6%、酶解温度55℃、酶解时间70 min,在此条件下酶解产物的抗氧化性最高,·OH清除率达21. 62%;超滤分离所得组分相对分子质量越小,抗氧化性越强,相对分子质量小于3 kDa组分的抗氧化性最高,·OH清除率达29. 54%,DPPH·清除率达22. 05%,还原力(OD值)达1. 298。

Optimization of enzymatic hydrolysis conditions and fractionation preparation of black bean antioxidant peptide

The effects of dosage of enzyme,mass fraction of substrate,enzymatic hydrolysis temperature and enzymatic hydrolysis time on antioxidant activity and hydrolysis degree of hydrolysates from black bean protein isolate by Alcalase hydrolysis were studied. The optimal hydrolysis conditions were determined by single factor experiment and orthogonal experiment. The black bean protein hydrolysates were separated by ultrafiltration with different relative molecular weight cut-off,and the antioxidant activities of the components obtained were determined. The results showed that the optimal hydrolysis conditions were obtained as follows: dosage of enzyme 3%,mass fraction of substrate 6%,enzymatic hydrolysis temperature 55 ℃,and enzymatic hydrolysis time 70 min. Under these conditions,the hydrolysates showed the highest antioxidant activity,and the hydroxyl radical scavenging rate reached 21. 62%.The smaller the relative molecular weight of the fractions obtained by ultrafiltration separation,the stronger the antioxidant activity. The fraction with the relative molecular weight less than 3 kDa exhibited the highest antioxidant activity,and its hydroxyl radical scavenging rate,DPPH radical scavenging rate and reducing power were 29. 54%,22. 05% and 1. 298,respectively.