The encapsulation of curcumin in micellar caseins (MCs) and the production of powder were performed by spray-drying. Nearly 97% of the curcumin was retained and the yellow powder showed a typical high casein powder morphology. The hygroscopic properties were determined, slight differences reflected less available hydrophobic sites when curcumin was bound to casein, favoring interactions with water in curcumin-enriched MC powders. No difference was detected on the internal MC structure via SAXS. The antioxidant activity of doped-curcumin powder presented 88% of active curcumin. For 60 days at 40 °C storage, the antioxidant activity of curcumin measured by ABTS and FRAP assays was preserved with a percentage of 82 ± 2.0% and 84 ± 1.1%, respectively. Curcumin doped powders presented similar features to classical casein powders (rehydration and gelling abilities). It was demonstrated that curcumin encapsulation in MCs in its powder form helped in protecting its antioxidant activity without influencing the techno-functional properties of MCs. This study allowed the incorporation of curcumin via the MC matrix as an active food ingredient available in a powder state usable as classical milk powder in several food formulations.

中文翻译：

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喷雾干燥制得的姜黄素掺杂酪蛋白胶束粉末的结构，凝胶化和抗氧化性能†

姜黄素在胶束酪蛋白（MCs）中的包封和粉末的生产通过喷雾干燥进行。保留了近97％的姜黄素，黄色粉末显示出典型的高酪蛋白粉末形态。确定了吸湿性，当姜黄素与酪蛋白结合时，细微差异反映了较少的可用疏水位点，有利于富含姜黄素的MC粉与水的相互作用。在内部MC结构上未检测到任何差异SAXS。掺杂姜黄素粉末的抗氧化活性占活性姜黄素的88％。在40°C下储存60天，通过ABTS和FRAP分析测得的姜黄素抗氧化活性分别保持为82±2.0％和84±1.1％。姜黄素掺杂的粉末具有与经典酪蛋白粉末类似的特征（补水和胶凝能力）。已经证明姜黄素以粉末形式包封在MC中有助于保护其抗氧化活性而不影响MC的技术功能性质。这项研究允许姜黄素通过MC基质作为一种活性食品成分掺入到粉末状态，可以用作几种食品配方中的经典奶粉。