大孔吸附树脂提取苦味乳清蛋白水解物及其功能性质和生物活性的研究

Use of Macroporous Adsorption Resin for Simultaneous Desalting and Debittering of Whey Protein Hydrolysates

用生物蛋白酶NAmanoG水解乳清分离蛋白(WPI),水解过程中因不断加碱引入的过多的灰分用大孔吸附树脂除去,吸附的水解产物用20%(HS20)、40%(HS40)和75%(HS75)乙醇洗脱,根据洗脱所用的乙醇浓度的不同可以将洗脱的产品分为HS20、HS40、HS75三个组分,分析这三组分的表面疏水性(SH0),血管紧张素-转换酶(ACE)的抑制作用,乳化特性(EAI),氨基酸组分和分子量分布。结果表明HS75具有最好的ACE抑制作用,疏水性氨基酸含量最高,相对分子质量小于600Da占71%,不存在相对分子质量超过4142Da的组分。盐几乎完全从大孔吸附树脂吸附物中被除去且水解物回收率高。乙醇解吸可能改变了溶剂的相互作用,削弱了多肽链和树脂之间的疏水相互作用,从而使水解物从吸附的树脂上被洗脱。

Whey protein isolate, WPI, was hydrolyzed using Protease N “Amano” G （IUB 3.4.24.28） in a batch reactor at 55℃ and pH7.0 according to the pH-stat procedure. Ash was removed by adsorbing the hydrolysates onto macroporous adsorption resins （MAR）. Desorption was achieved by washing with 20%, 40% and 75% alcohol （V/V） respectively and three fractions： HS20, HS40 and HS75 corresponding to the alcohol concentrations used in desorption were obtained. They were assayed for surface hydrophobicity （SH0）, angiotensin-I converting enzyme （ACE） inhibition, emulsifying activity index （EAI）, total amino acid composition and molecular weight distribution. Fraction HS75 showed superior ACE inhibition effect （lowest IC50）, with highest content of hydrophobic and essential amino acids and contained about 71% less 600Da with no fractions exceeding 4142Da. Additionally; the hydrolyte showed the objectionable bitterness. Desorption with alcohol reversed the solvent antagonism, weaken hydrophobic interaction forces between the peptides and resins and hence to elute the peptides.