本研究主要探讨了pH对藻蓝蛋白（C-PC）理化性质以及乳化性质的影响。先通过测定C-PC在不同pH（3、5、7、9、11）条件下的溶解性、表面电位（ζ）、表面疏水性（H0）、光谱学性质以及透射电镜（TEM）图，对其理化性质进行了表征。以C-PC为乳化剂，大豆油为油相制备乳液（油相比例φ=0.2），通过测定油滴粒径分布、絮凝及凝结情况、分层指数以及氧化产物等多个指标评估pH对C-PC乳化性质的影响。结果表明1 wt% C-PC溶液在实验pH范围内，溶解性均较好（最低为69.15%）；C-PC在pH 3及11条件下，多聚体会发生解聚，肽链发生展开，表面疏水性也得到显著提升，pH 5~7内H0为200~650，而pH 3及11分别为1703和1261。因此，C-PC在pH 3和pH 11条件下乳化表现较好，乳液液滴有着较小的粒径和较好的储藏稳定性。而C-PC在其他pH条件下乳化能力相对较低，且不稳定。此外各pH条件下的C-PC乳液均能较好地抑制乳液中油脂的氧化，但在pH 5~9条件下的抑制油脂氧化的表现要稍好于pH 3和pH 11。通过本文可以了解到C-PC在酸性以及碱性条件下的乳化性表现均较好，再加上它具有的优越的抗氧化活性，拥有成为天然抗氧化型乳化剂的潜力。

The effect of pH on the physicochemical properties and emulsifying characteristics of C-phycocyanin (C-PC) was examined. The physicochemical properties of C-PC at different pHs (3, 5, 7, 9, 11) were determined through examining C-PC’s solubility, surface potential (ζ), surface hydrophobicity (H0), spectroscopic behaviors, and surface features (by transmission electron microscopy (TEM)). Using C-PC as an emulsifier and soybean oil as the oil phase, emulsion (oil ratio φ=0.2) was prepared, and the oil droplet size distribution, extents of flocculation and coagulation, creaming index and oxidation products were be determined to evaluate the effect of pH on the emulsifying properties of C-PC. The results showed that the 1 wt% C-PC solutions all had good solubility in the experimental pH range (minimum solubility: 69.15%); At pH 3 or 11, the C-PC polymer would depolymerize, with the peptide chains unfolding and the surface hydrophobicity increasing significantly. H0 was 200~650 at pH 5~7, whereas, the H0 values were 1703 and 1261 at pH 3 and 11, respectively. Therefore, at pH 3 or pH 11, emulsification was achieved to a greater extent along with smaller particle size and higher storage stability. The emulsifying ability of C-PC at other pHs was relatively low and the corresponding emulsion was unstable. In addition, oil oxidation was inhibited in all of the C-PC emulsions at different pHs, but slightly greater inhibition of oil oxidation was achieved at pH 5~9 than at pH 3 or 11. As shown in this paper, C-PC exhibits good emulsifying properties at acidic and alkaline pHs and possesses superior antioxidant activity, therefore, has the potential to be a natural and antioxidative emulsifier.

国家自然科学基金资助项目（31771917）