Peng Dengfeng, Yang Jinchu, Li Jing, Tang Cuie, Li Bin
Key Laboratory of Environment Correlative Dietology, Ministry of Education, Huazhong Agricultural University , Wuhan, Hubei 430070, People's Republic of China.
Technology Center, China Tobacco Henan Industrial Company Limited , Zhengzhou, Henan 450000, People's Republic of China.
J Agric Food Chem. 2017 Dec 6;65(48):10658-10665. doi: 10.1021/acs.jafc.7b03669. Epub 2017 Nov 28.
β-Lactoglobulin fibrils could serve as a surface-active component and form adsorption layers at the air/water interface. In this study, the physical parameters related to the surface adsorption, foaming, and surface properties of β-lactoglobulin fibrils as a function of pH (2-8) were investigated. Results showed that an increase of pH from 2 to 5 led to a rise of the viscoelastic modulus of the surface adsorption layer and half-life time (t) of foams, but it decreased foamability. When the pH was close to its isoelectric point (5.2), fibrils had the lowest electrostatic repulsion and entangled at the air/water interface resulting in a tightly packaged adsorption layer around bubbles to prevent coalescence and coarsening. When the pH (7-8) was higher than the pI of fibrils, the negatively charged β-lactoglobulin fibrils possessed good foamability (∼80%) and high foam stability (t ≈ 8 h) simultaneously even at low concentration (1 mg/mL). It demonstrated that β-lactoglobulin fibrils with negative charges presented a good foaming behavior and could be a potential new foaming agent in the food industry.
β-乳球蛋白纤维可作为一种表面活性成分，并在空气/水界面形成吸附层。在本研究中，研究了与β-乳球蛋白纤维在pH值（2 - 8）范围内的表面吸附、发泡及表面性质相关的物理参数。结果表明，pH值从2增加到5会导致表面吸附层的粘弹性模量和泡沫半衰期（t）升高，但发泡性降低。当pH值接近其等电点（5.2）时，纤维具有最低的静电排斥力，并在空气/水界面缠结，从而在气泡周围形成紧密包裹的吸附层，以防止聚结和粗化。当pH值（7 - 8）高于纤维的pI时，即使在低浓度（1 mg/mL）下，带负电荷的β-乳球蛋白纤维也同时具有良好的发泡性（约80%）和高泡沫稳定性（t≈8 h）。这表明带负电荷的β-乳球蛋白纤维具有良好的发泡性能，可能成为食品工业中一种潜在的新型发泡剂。
