Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun, Jilin, 130062, China.
Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun, Jilin, 130062, China; Department of Nutrition and Food Sciences, College of Agricultural and Life Sciences, University of Vermont, Burlington 05405; Department of Food Science, Northeast Agriculture University, Harbin, Heilongjiang, 150030, China.
J Dairy Sci. 2018 Nov;101(11):9680-9692. doi: 10.3168/jds.2018-14998. Epub 2018 Sep 7.
Soybean lecithin is often used as a surfactant in food formulation. The aim of this study was to investigate the interactions between soybean lecithin (SL, 0-3%, wt/vol) and whey protein (WP, 10%, wt/vol) or polymerized whey protein (PWP, 10%, wt/vol) induced by heating WP solutions at 85°C for 0 to 20 min at pH 7.0. The samples were evaluated for zeta potential, particle size, morphology, rheological properties, thermal properties, secondary structure, and surface hydrophobicity. Zeta potential of WP increased linearly as SL level increased from 0 to 3%, whereas that of PWP changed with plateau at SL level of 1%, which may be due to the aggregation of SL. The addition of SL increased the particle size and apparent viscosity of both WP and PWP. All the samples exhibited different morphology depending on SL level and heating time according to transmission electron microscopy images. Whey protein showed obviously decreased gelation time and increased storage modulus in the presence of SL. Differential scanning calorimetry curves confirmed the effects of SL on the thermal properties of both WP and PWP. Circular dichroism spectra indicated that SL had effects on the secondary structure of both WP and PWP. The changes in surface hydrophobicity indicated the hydrophobic interactions between WP/PWP and SL. Data indicate that the physicochemical and functional properties of WP and PWP can be altered by adding soybean lecithin.
大豆卵磷脂通常被用作食品配方中的表面活性剂。本研究的目的是研究大豆卵磷脂（SL，0-3％，wt/vol）与乳清蛋白（WP，10％，wt/vol）或聚合乳清蛋白（PWP，10％，wt/vol）之间的相互作用，方法是将 WP 溶液在 pH7.0 下加热 85°C0-20 分钟。样品的评估指标包括动电位、粒径、形态、流变特性、热特性、二级结构和表面疏水性。随着 SL 水平从 0 增加到 3％，WP 的动电位呈线性增加，而 PWP 的动电位则在 SL 水平为 1％时呈平台变化，这可能是由于 SL 的聚集。添加 SL 会增加 WP 和 PWP 的粒径和表观粘度。根据透射电子显微镜图像，所有样品的形态都因 SL 水平和加热时间的不同而不同。在 SL 的存在下，乳清蛋白的凝胶化时间明显缩短，储存模量增加。差示扫描量热法曲线证实了 SL 对 WP 和 PWP 热性能的影响。圆二色光谱表明 SL 对 WP 和 PWP 的二级结构有影响。表面疏水性的变化表明 WP/PWP 与 SL 之间存在疏水相互作用。数据表明，添加大豆卵磷脂可以改变 WP 和 PWP 的物理化学和功能特性。
