Key Laboratory of Food Nutrition and Safety (Tianjin University of Science & Technology), Ministry of Education, Tianjin 300457, China; Tianjin Food Engineering Center, Tianjin 300457, China.
Key Laboratory of Food Nutrition and Safety (Tianjin University of Science & Technology), Ministry of Education, Tianjin 300457, China.
Int J Biol Macromol. 2018 Dec;120(Pt A):34-44. doi: 10.1016/j.ijbiomac.2018.08.070. Epub 2018 Aug 16.
In this article, oil-in-water (O/W) emulsions stabilized by natural whey protein concentrate (WPC) and microparticulated whey protein (MWP) and their mixtures with xanthan gum (XG) were prepared to investigate the lipid oxidative stability of O/W emulsions with the same interfacial composition but different interfacial structures. High-performance size exclusion chromatography, Fourier transform infrared spectrometry, X-ray diffraction analysis and steady-state fluorescence spectroscopy were used to reveal the differences in the structures of natural whey protein and the microparticulated whey proteins (MWP, pH 3.5-8.5). Dispersions of the proteins (70% w/w) and XG (30% w/w) were mixed to prepare the mixtures (protein-XG). Emulsions of 60% peanut oil that were stabilized by the proteins and the protein-XG mixtures were subjected to oxidation. In addition, the peroxide values (PVs) were measured to evaluate the oxidative stability of each emulsion. The MWP(pH 4.5)-XG and MWP(pH 6.5)-XG-stabilized emulsions showed high oxidative stabilities that were not significantly different from each other. The results indicated that a single complex layer formed by the spherical protein microparticles and XG can better inhibit the lipid oxidation of O/W emulsions than a double layer. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.
本文制备了由天然乳清蛋白浓缩物（WPC）和微粒化乳清蛋白（MWP）稳定的油包水（O/W）乳液及其与黄原胶（XG）的混合物，以研究具有相同界面组成但不同界面结构的 O/W 乳液的脂质氧化稳定性。采用高效尺寸排阻色谱、傅里叶变换红外光谱、X 射线衍射分析和稳态荧光光谱法揭示了天然乳清蛋白和微粒化乳清蛋白（MWP，pH 3.5-8.5）的结构差异。将蛋白质（70%w/w）和 XG（30%w/w）的分散体混合制备混合物（蛋白-XG）。用蛋白质和蛋白-XG 混合物稳定的 60%花生油乳液进行氧化。此外，还测量了过氧化物值（PV）以评估每种乳液的氧化稳定性。MWP（pH 4.5）-XG 和 MWP（pH 6.5）-XG 稳定的乳液具有较高的氧化稳定性，彼此之间没有明显差异。结果表明，由球形蛋白质微粒和 XG 形成的单一复合层可以比双层更好地抑制 O/W 乳液的脂质氧化。本研究对开发易氧化的含脂质相的新型结构具有重要意义。
