Abstract：
Limited proteolysis, CaCl2 and carboxymethyl cellulose (CMC) have individually demonstrated ability to increase the gel strength of laboratory-extracted plant proteins. However, the syneresis effects of their combination on the gelling capacity of commercial plant protein remains unclear. This was investigated by measuring the rheological property, microstructure and protein-protein interactions of gels formed from Alcalase hydrolyzed or intact pea proteins in the presence of 0.1 % CMC and 0-25 mM CaCl2. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed the molecular weight of pea protein in the mixture were < 15 kDa after hydrolysis. The hydrolysates showed higher intrinsic fluorescence intensity and lower surface hydrophobicity than the intact proteins. Rheology showed that the storage modulus (G\') of hydrolyzed pea protein (PPH)-based gels sightly decreased compared to those of native proteins. 5-15 mM CaCl2 increased the G\' for both PP and PPH-based gels and decreased the strain in the creep-recovery test. Scanning electron microscopy (SEM) showed the presence of smaller protein aggregates in the PPH-based gels compared to PP gels and the gel network became denser, and more compact and heterogenous in the presence of 15 and 25 mM CaCl2. The gel dissociation assay revealed that hydrophobic interactions and hydrogen bonds were the dominant forces to maintain the gel structure. In vitro digestion showed that the soluble protein content in PPH-based gels was 10 ∼ 30 % higher compared to those of the PP counterpart. CaCl2 addition reduced protein digestibility with a concentration dependent behavior. The results obtained show contrasting effects of limited proteolysis and CaCl2 on the gelling capacity and digestibility of commercial pea proteins. These findings offer practical guidelines for developing pea protein-based food products with a balanced texture and protein nutrition through formulation and enzymatic pre-treatment.
摘要：
有限的蛋白水解，CaCl2和羧甲基纤维素（CMC）分别证明了增加实验室提取的植物蛋白凝胶强度的能力。然而,它们的组合对商业植物蛋白的胶凝能力的影响尚不清楚。这是通过测量流变性质来研究的，在0.1％CMC和0-25mMCaCl2存在下，由Alcalase水解或完整豌豆蛋白形成的凝胶的微观结构和蛋白质-蛋白质相互作用。十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)显示水解后混合物中豌豆蛋白的分子量<15kDa。水解产物显示出比完整蛋白质更高的固有荧光强度和更低的表面疏水性。流变学表明，与天然蛋白质相比，基于水解豌豆蛋白（PPH）的凝胶的储能模量（G'）明显下降。5-15mMCaCl2增加了PP和PPH基凝胶的G\'，并降低了蠕变恢复试验中的应变。扫描电子显微镜（SEM）显示，与PP凝胶相比，PPH基凝胶中存在较小的蛋白质聚集体，并且凝胶网络变得更加致密。在15和25mMCaCl2的存在下更加紧凑和异质。凝胶解离实验表明，疏水相互作用和氢键是维持凝胶结构的主导力量。体外消化表明，与PP对应物相比，PPH基凝胶中的可溶性蛋白质含量高10〜30％。添加CaCl2会降低蛋白质的消化率，并具有浓度依赖性。获得的结果表明，有限的蛋白水解和CaCl2对市售豌豆蛋白的胶凝能力和消化率的影响相反。这些发现为通过配方和酶预处理开发具有平衡质地和蛋白质营养的基于豌豆蛋白质的食品提供了实用指南。
