Colloid particles consisting of biopolymers such as proteins and polysaccharides have been widely used as food or drug components. Here we investigate the interactions and structures in aqueous solutions of ovalbumin (OVA) and κ-carrageenan (CRG) to unravel the complexation mechanism. The pH titration results for the OVA/CRG solution (0.025%:0.025% by mass) indicate the structural transition of the OVA/CRG complexes happens during acidification. Significant accumulation of insoluble OVA/CRG complex coacervates with OVA packed in the hydrophobic structures formed by CRG occurs when pH is lower than the isoelectric point of OVA. The highest turbidity is reached at pH = 3.0 because of the strongest electrostatic attraction, and further deceasing pH leads to the dissociation of complex coacervates. Composition and ionic strength show significant effects on turbidity and aggregates formation by tuning electrostatic interactions between N–H⁺ of –NH₃⁺ on OVA and S–O^– of –SO₃^– on CRG.

由生物聚合物如蛋白质和多糖组成的胶体颗粒已被广泛用作食品或药物成分。在这里，我们研究卵清蛋白（OVA）和κ角叉菜胶（CRG）在水溶液中的相互作用和结构，以阐明络合机理。OVA / CRG溶液的pH滴定结果（0.025％：0.025％质量）表明OVA / CRG配合物的结构转变发生在酸化过程中。当pH值低于OVA的等电点时，不溶性OVA / CRG复合物的凝聚层会大量聚集，其中OVA堆积在CRG形成的疏水结构中。由于最强的静电吸引力，在pH = 3.0时达到最高浊度，并且pH值进一步降低会导致复合凝聚层解离。⁺ -NH的₃ ⁺对OVA和S-O ^-的-SO ₃ ^-上CRG。