Oliveira Maria Mariana Garcia de, Fessori Ana Gabriela Baroni Wicher, Huamaní-Meléndez Víctor Justiniano, Ferreira Júnior Sérgio Luís, Caruso Ícaro Putinhon, Mauro Maria Aparecida
Department of Food Engineering and Technology, Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (UNESP), Street Cristóvão Colombo, 2265, São José do Rio Preto 15054-000, Brazil.
Department of Physics, Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (UNESP), Street Cristóvão Colombo, 2265, São José do Rio Preto 15054-000, Brazil.
Int J Biol Macromol. 2025 Mar;296:139727. doi: 10.1016/j.ijbiomac.2025.139727. Epub 2025 Jan 9.
In response to the growing need to expand the knowledge base on novel, more sustainable protein sources, this study investigated the effectiveness of cowpea protein concentrate (CPC) as a natural emulsifying agent, examining the relationships between pH (3-11), oil concentration (2-10 %), and emulsion stability. pH and oil concentration significantly impacted droplet size distribution, with uniformity decreasing in the order of pH 9 > pH 11 > pH 7, which was attributed to droplet coalescence and flocculation. As evidenced by circular dichroism, alkalinity induced a slight increase in the beta-sheet content of CPC, while simultaneously reducing the alpha-helix content. Rheological analysis of CPC-stabilized emulsions revealed a transition from shear-thinning to thickening flow behavior at higher shear rates. At pH 7, viscosity decreased with increasing oil concentration, whereas this effect was less pronounced in alkaline media. Alkalinity also prevented aggregation of oil droplets when emulsions were heated. At pH 3 and 5, phase separation occurred within 24 h. Emulsions at pH 9 and 11 exhibited the highest stability over a 30-day storage period, while the lowest stability (pH 7) was correlated with increased particle mobility. In most cases, at neutral and alkaline pH, CPC proved to be an effective emulsifying agent, demonstrating its ability to enhance stability by preventing coalescence and sedimentation.
为了满足扩大关于新型、更可持续蛋白质来源知识库的日益增长的需求，本研究调查了豇豆浓缩蛋白（CPC）作为天然乳化剂的有效性，研究了pH值（3 - 11）、油浓度（2 - 10%）与乳液稳定性之间的关系。pH值和油浓度对液滴尺寸分布有显著影响，均匀性按pH 9 > pH 11 > pH 7的顺序降低，这归因于液滴聚结和絮凝。圆二色性表明，碱性导致CPC的β-折叠含量略有增加，同时α-螺旋含量降低。对CPC稳定乳液的流变学分析表明，在较高剪切速率下，其流动行为从剪切稀化转变为剪切增稠。在pH 7时，粘度随油浓度的增加而降低，而在碱性介质中这种影响不太明显。碱性还能防止乳液加热时油滴聚集。在pH 3和5时，24小时内会发生相分离。pH 9和11的乳液在30天的储存期内表现出最高的稳定性，而最低稳定性（pH 7）与颗粒流动性增加有关。在大多数情况下，在中性和碱性pH条件下，CPC被证明是一种有效的乳化剂，表明它能够通过防止聚结和沉淀来提高稳定性。
