乙二胺四乙酸（EDTA）和柠檬酸盐对含氯化钙的乳清蛋白稳定水包油乳液理化性质的影响

Influence of EDTA and citrate on physicochemical properties of whey protein-stabilized oil-in-water emulsions containing CaCl2.

作者信息

Keowmaneechai E, McClements D J

机构信息

Department of Food Technology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakornpathom 73000, Thailand.

出版信息

J Agric Food Chem. 2002 Nov 20;50(24):7145-53. doi: 10.1021/jf020489a.

DOI:10.1021/jf020489a

PMID:12428974

Abstract

The influence of chelating agents (disodium ethylenediaminetetraacetate (EDTA) and sodium citrate) on the physicochemical properties of whey protein isolate (WPI)-stabilized oil-in-water emulsions containing calcium chloride was determined. The calcium-binding characteristics of EDTA and citrate at 30 degrees C were characterized in aqueous solutions (20 mM Tris buffer, pH 7.0) by isothermal titration calorimetry (ITC). EDTA and citrate both bound calcium ions in a 1:1 ratio, but EDTA had a much higher binding constant. Oil-in-water emulsions (pH 7.0) were prepared containing 6.94% (w/v) soybean oil, 0.35% (w/v) WPI, 0.02% (w/v) sodium azide, 20 mM Tris buffer, 10 mM CaCl(2), and 0-40 mM chelating agent. The particle size, apparent viscosity, creaming stability, free calcium concentration, and particle surface potential of the emulsions were measured. The chelating agents reduced or prevented droplet aggregation in the emulsions. When they were present above a certain concentration (>3.5 mM EDTA or >5 mM citrate), droplet aggregation was prevented. The reduction of aggregation was indicated by decreases in particle size, shear-thinning behavior, apparent viscosity, and creaming. Emulsions containing chelating agents had lower free calcium concentrations and more negatively charged droplets, indicating that the chelating agents improved emulsion stability by binding calcium ions. EDTA could be used at lower concentrations than citrate because of its higher calcium ion binding constant.

摘要

测定了螯合剂（乙二胺四乙酸二钠（EDTA）和柠檬酸钠）对含有氯化钙的乳清蛋白分离物（WPI）稳定的水包油乳液物理化学性质的影响。通过等温滴定量热法（ITC）在水溶液（20 mM Tris缓冲液，pH 7.0）中表征了30℃下EDTA和柠檬酸盐的钙结合特性。EDTA和柠檬酸盐均以1:1的比例结合钙离子，但EDTA具有更高的结合常数。制备了水包油乳液（pH 7.0），其含有6.94%（w/v）大豆油、0.35%（w/v）WPI、0.02%（w/v）叠氮化钠、20 mM Tris缓冲液、10 mM CaCl₂和0 - 40 mM螯合剂。测量了乳液的粒径、表观粘度、乳析稳定性、游离钙浓度和颗粒表面电位。螯合剂减少或防止了乳液中的液滴聚集。当它们的浓度高于一定值（>3.5 mM EDTA或>5 mM柠檬酸盐）时，可防止液滴聚集。粒径减小、剪切变稀行为、表观粘度和乳析现象的降低表明聚集作用减弱。含有螯合剂的乳液具有较低的游离钙浓度和带更多负电荷的液滴，这表明螯合剂通过结合钙离子提高了乳液稳定性。由于EDTA具有更高的钙离子结合常数，因此其使用浓度可比柠檬酸盐低。