卵磷脂对乳清分离蛋白乳液性质和乳液凝胶结构特性及其所负载β-胡萝卜素的影响

Effects of lecithin on the emulsion properties, emulsion gel structure characteristics and its loaded β-carotene of whey isolate protein

中文关键词:  乳清分离蛋白  卵磷脂  乳液凝胶  流变特性  稳定性

英文关键词:whey protein isolate  lecithin  emulsion gel  rheological properties  stability

中文摘要:

      目的 研究卵磷脂(lecithin, LEC)添加对乳清分离蛋白(whey protein isolate, WPI)乳液的理化性质和乳液凝胶体系的微观结构、流变特性及其所负载β-胡萝卜素热稳定性的影响。方法 以未添加LEC乳液为对照, 测定添加不同浓度LEC (0.1%~0.5%)所制备WPI乳液的粒径、ζ-电位及乳液稳定性, 并将上述乳液经酸诱导处理后制成乳液凝胶, 分析其微观结构形态、流变特性及所负载β-胡萝卜素热稳定性的变化。结果 LEC可通过降低蛋白质溶液的界面张力而使得其乳液的粒径、多分散系数(polydispersity, PDI)值降低, 从而有效改善乳液的稳定性; 同时LEC的加入显著提高了WPI-LEC乳液凝胶的表观黏度和黏弹性模量, 表明有助于形成结构更加紧密的乳液凝胶体系, 使得β-胡萝卜素在100℃加热10 h后保留率可达60%。结论 通过添加LEC来提高WPI乳液的稳定性, 可以有效改善其乳液凝胶的流变特性和微观结构, 从而增强所负载β-胡萝卜素的稳定性。

英文摘要:

      Objective To investigate the effect of lecithin (LEC) addition on the physicochemical properties of whey protein isolate (WPI) emulsions, and the microstructure, rheological properties of the emulsion gel system as well as the thermal stability of the loaded β-carotene. Methods Without the addition of LEC emulsion as control, the particle size, ζ-potential and emulsion stability of WPI emulsions prepared by adding different concentrations (0.1%?0.5%) of LEC were measured. Further, the emulsion gels were produced by acid-inducted treatment and the changes in microstructure morphology, rheological properties and thermal stability of the loaded β-carotene were analyzed. Results The LEC could reduce the particle size and polydispersity (PDI) values of protein emulsions by reducing the interfacial tension of the protein solution, which facilitated the improvement of the stability of emulsions. Meanwhile the addition of LEC significantly increased the apparent viscosity and viscoelastic modulus of WPI-LEC emulsion gels, indicating that it contributed to the formation of a more compact emulsion gel system, resulting in a retention rate of β-carotene of 60% after heating at 100℃ for 10 h. Conclusion The addition of LEC can facilitate the stability of WPI emulsions, which can effectively improve the rheological properties and microstructure of their emulsion gels, thus enhancing the stability of the loaded β-carotene.