Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences, Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences, Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs, Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China.
Int J Biol Macromol. 2024 Nov;280(Pt 2):135794. doi: 10.1016/j.ijbiomac.2024.135794. Epub 2024 Sep 19.
This study examines the effects of protein glutaminase modification on the interfacial properties and emulsion stability of pea protein isolates (PPI). Emulsions were prepared using native (NPPI) and deamidated PPI (DPPI) at concentrations from 0.5 wt% to 3.6 wt%. The stability of these emulsions was evaluated by examining droplet size distribution, flocculation index, ζ-potential, and CLSM. DPPI demonstrated superior emulsifying ability and stability, requiring only 2.0 wt% to prevent flocculation compared to NPPI's 3.6 wt%. Interfacial properties, such as protein coverage, composition, thickness, tension, and rheology, were characterized. Large Amplitude Oscillatory Dilatation analysis showed minimal differences between NPPI and DPPI-stabilized interfaces at 1 wt%. However, at 3.6 wt%, NPPI interfaces demonstrated abrupt intra-cycle yielding and viscous behavior, whereas DPPI interfaces exhibited gradual softening and a higher maximum linear strain. Additionally, DPPI showed higher interfacial protein coverage and lower interfacial tension. NPPI formed dense, brittle films prone to rupture under dynamic deformation, leading to poor stability. Deamidation of PPI unfolded the protein structure, exposing hydrophobic groups and increasing carboxyl groups, which reduced aggregation. This resulted in a uniform, extensible, and elastic interfacial film resistant to large deformations. Thus, DPPI-stabilized emulsions demonstrated superior stability, showcasing their potential for industrial applications.
本研究考察了蛋白质谷氨酰胺酶修饰对豌豆分离蛋白（PPI）界面性质和乳液稳定性的影响。使用天然（NPPI）和去酰胺化 PPI（DPPI）在 0.5wt%至 3.6wt%的浓度下制备乳液。通过考察液滴尺寸分布、絮聚指数、ζ-电位和 CLSM 评估这些乳液的稳定性。与 NPPI 的 3.6wt%相比，DPPI 表现出优异的乳化能力和稳定性，仅需 2.0wt%即可防止絮聚。界面性质，如蛋白质覆盖度、组成、厚度、张力和流变学等进行了表征。大振幅振荡扩张分析表明，在 1wt%时 NPPI 和 DPPI 稳定的界面之间几乎没有差异。然而，在 3.6wt%时，NPPI 界面在每个循环内表现出突然的屈服和粘性行为，而 DPPI 界面表现出逐渐软化和更高的最大线性应变。此外，DPPI 表现出更高的界面蛋白质覆盖度和更低的界面张力。NPPI 形成致密、易碎的薄膜，在动态变形下容易破裂，导致稳定性差。PPI 的去酰胺作用使蛋白质结构展开，暴露出疏水性基团并增加羧基基团，从而减少聚集。这导致了均匀、可拉伸和弹性的界面膜，能够抵抗大变形。因此，DPPI 稳定的乳液表现出优异的稳定性，展示了其在工业应用中的潜力。
