生物解离大豆蛋白酶解物体外模拟消化抗氧化活性变化

挤压膨化大豆在生物解离过程中,通过酶解(碱性蛋白酶、风味蛋白酶)产生的大豆蛋白酶解物(soybean protein hydrolysate,SPH)有良好的抗氧化活性,因此,需要探索模拟胃肠道(gastrointestinal,GI)消化对蛋白酶解物抗氧化活性的影响。分别以蛋白酶(碱性蛋白酶、风味蛋白酶)酶解得到的SPH和经过模拟GI消化后的产物作为研究对象,采用水解度、氨基酸组成、分子质量分布、氧化自由基吸收能力(oxidative radical absorption capacity,ORAC)、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力及2,2’-联氨-双(3-乙基苯并噻唑啉-6-磺酸)(2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt,ABTS)阳离子自由基清除能力对样品抗氧化活性进行分析。结果显示:相对于风味蛋白酶酶解,采用碱性蛋白酶进行酶解时抗氧化活性更高;但是经过模拟GI消化后,风味蛋白酶酶解得到的SPH抗氧化活性更高,ORAC为69.15μmol/mg、DPPH自由基清除能力为27.29%、ABTS阳离子自由基清除能力为56.21%,肽的相对含量更高,为75.86%,并且肽中具有抗氧化活性的氨基酸含量更高,分子质量小于1 kDa的肽相对含量最高,为17.35%。

Changes in Antioxidant Activity of Soybean Protein Hydrolysates from Enzyme-Assisted Aqueous Extraction of Oil under Simulated Gastrointestinal Digestion

During the enzyme-assisted aqueous extraction of oil from extruded soybean, soybean protein hydrolysates (SPHs) with strong antioxidant capacity are produced by enzymatic hydrolysis (alcalase and flavourzyme). Thus, it is necessary to study the effect of simulated gastrointestinal (GI) digestion on antioxidant properties of SPHs. In this study, the alcalase and flavourzyme hydrolysates were subjected to simulated GI digestion. The degree of hydrolysis (DH) during digestion, amino acid composition, and molecular mass distribution were determined. Antioxidant properties were evaluated by oxidative radical absorption capacity (ORAC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and 2,2’-azinobis- (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) cation radical scavenging assays. The results showed that the alcalase hydrolysate had higher antioxidant activity compared with the flavourzyme hydrolysate, while the opposite was observed when we compared their digests. The antioxidant activity of the digest of the flavourzyme hydrolysate was determined to be 69.15 μmol/mg, 27.29% and 56.21% in the ORAC, DPPH and ABTS cation radical scavenging assays, respectively, and it had a higher peptide content of 75.86%. Moreover, the peptides had higher levels of amino acids with antioxidant activity and fractions with a molecular mass of less than 1 kDa were the most dominant, accounting for 17.35% of the total peptides.