Pérez-Gago M B, Krochta J M
Department of Food Science and Technology, University of California, Davis, California 95616, USA.
J Agric Food Chem. 2001 Feb;49(2):996-1002. doi: 10.1021/jf000615f.
Lipid particle size effects on water vapor permeability (WVP) and mechanical properties of whey protein isolate (WPI)/beeswax (BW) emulsion films were investigated. Emulsion films containing 20 and 60% BW (dry basis) and mean lipid particle sizes ranging from 0.5 to 2.0 microm were prepared. BW particle size effects on WVP and mechanical properties were observed only in films containing 60% BW. WVP of these films decreased as lipid particle size decreased. As drying temperature increased, film WVPs decreased significantly. Meanwhile, tensile strength and elongation increased as BW particle size decreased. However, for 20% BW emulsion films, properties were not affected by lipid particle size. Results suggest that increased protein-lipid interactions at the BW particle interfaces, as particle size decreased and resulting interfacial area increased, result in stronger films with lower WVPs. Observing this effect depends on a large lipid content within the protein matrix. At low lipid content, the effect of interactions at the protein-lipid interfaces is not observed, due to the presence of large protein-matrix regions of the film without lipid, which are not influenced by protein-lipid interactions.
研究了脂质颗粒大小对乳清分离蛋白（WPI）/蜂蜡（BW）乳液膜水蒸气透过率（WVP）和机械性能的影响。制备了含有20%和60% BW（干基）且平均脂质颗粒大小在0.5至2.0微米范围内的乳液膜。仅在含有60% BW的膜中观察到BW颗粒大小对WVP和机械性能的影响。这些膜的WVP随着脂质颗粒大小的减小而降低。随着干燥温度升高，膜的WVP显著降低。同时，随着BW颗粒大小减小，拉伸强度和伸长率增加。然而，对于含有20% BW的乳液膜，其性能不受脂质颗粒大小的影响。结果表明，随着颗粒大小减小且界面面积增加，BW颗粒界面处蛋白质 - 脂质相互作用增强，从而形成具有较低WVP的更强的膜。观察到这种效应取决于蛋白质基质中大量的脂质含量。在低脂质含量时，由于膜中存在无脂质的大蛋白质基质区域，这些区域不受蛋白质 - 脂质相互作用的影响，因此未观察到蛋白质 - 脂质界面处相互作用的效应。
