Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China; Department of Food Science, University of Massachusetts, Amherst, MA 01003, United States.
Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China.
Food Res Int. 2017 Jun;96:84-93. doi: 10.1016/j.foodres.2017.03.015. Epub 2017 Mar 11.
The aim of the present study was to fabricate catechin-egg white protein (CT-EWP) conjugates as novel food-grade antioxidant emulsifiers designed to improve the physicochemical stability of β-carotene (BC) emulsions. CT-EWP conjugates were synthesized using free radical grafting, and the formation of conjugates was confirmed by electrophoresis and liquid chromatography-mass spectrometry. The physicochemical stability of BC emulsions was characterized by measuring alterations in particle size, ζ-potential and BC retention. The particle size and ζ-potential changed more rapidly at 37°C than at 4 or 25°C, however no creaming or oiling-off were observed at any of the storage temperatures, suggesting all emulsions were physically stable throughout the 30-day storage period. Compared to emulsions stabilized by EWP or CT+EWP physical mixtures (no conjugation), CT-EWP conjugate-stabilized emulsions had better resistance to environmental stresses, such as thermal processing and high ionic strengths, which was attributed to a stronger steric repulsion between the oil droplets. CT-EWP conjugates also significantly reduced the degradation rate of BC in emulsions during storage (p<0.05), which was attributed to their strong antioxidant and interfacial activities. These results indicate that CT-EWP conjugates can be utilized to develop food-grade delivery systems to protect chemically labile lipophilic bioactive compounds.
本研究旨在制备儿茶素-蛋清蛋白（CT-EWP）缀合物作为新型食品级抗氧化乳化剂，以提高β-胡萝卜素（BC）乳液的物理化学稳定性。通过自由基接枝合成 CT-EWP 缀合物，并通过电泳和液相色谱-质谱法确认缀合物的形成。通过测量粒径、ζ-电位和 BC 保留率的变化来表征 BC 乳液的物理化学稳定性。在 37°C 下，粒径和 ζ-电位的变化比在 4°C 或 25°C 下更快，然而，在任何储存温度下都没有观察到分层或浮油现象，这表明所有乳液在 30 天的储存期内均保持物理稳定。与由 EWP 或 CT+EWP 物理混合物（无缀合）稳定的乳液相比，CT-EWP 缀合物稳定的乳液对环境应激（如热加工和高离子强度）具有更好的抵抗力，这归因于油滴之间更强的空间排斥作用。CT-EWP 缀合物还显著降低了乳液中 BC 在储存期间的降解速率（p<0.05），这归因于它们强大的抗氧化和界面活性。这些结果表明，CT-EWP 缀合物可用于开发食品级递送系统，以保护化学不稳定的亲脂性生物活性化合物。
