Emulsion is a commonly investigated bioactive loaded delivery system. The bioactive content and its location in oil phase primarily determine the quality and chemical stability of emulsion. In this study, Raman microspectroscopy was used to quantify α-tocopherol and to visualize its distribution in oil-in-water emulsion stabilized by whey protein isolates. Results suggested that α-tocopherol contents (25–300 g/kg) in corn oil with the integrating Raman intensity at 481.9 and 588.6 cm⁻¹ showed determination coefficient (R²) of 0.98 and 0.99, and limit of detection of 5.1 and 21.2 g/kg, respectively. For detecting α-tocopherol in emulsions, the relative standard deviation values from Raman method using intensities at 481.9 cm⁻¹ and 588.6 cm⁻¹ were in the ranges of 4%–16% and 2%–6%, respectively. The developed Raman method provided correlative results with those of HPLC method (R² = 0.99). Moreover, Raman chemical imaging depicted the non-homogeneous TOC distribution within oil droplets, where TOC had the trend of migrating to the interface of oil and water. This study provided a novel approach for functional emulsion analysis, which may serve the basis for designing stable and controllable release of emulsion systems in future.

乳剂是通常研究的生物活性负载递送系统。生物活性含量及其在油相中的位置主要决定乳液的质量和化学稳定性。在这项研究中，拉曼光谱用于量化α-生育酚，并可视化其在乳清蛋白分离物稳定的水包油乳液中的分布。结果表明，玉米油中α-生育酚含量（25-300 g / kg），拉曼积分强度分别为481.9和588.6 cm ^-1，测定系数（R ²）为0.98和0.99，检出限为5.1和21.2克/千克。为了检测乳液中的α-生育酚，使用481.9 cm ^-1和588.6 cm处的强度从拉曼方法得到的相对标准偏差值^-1的范围分别为4％–16％和2％–6％。发达的拉曼方法提供了与HPLC方法相关的结果（R ²  = 0.99）。此外，拉曼化学成像描述了油滴内非均匀的TOC分布，其中TOC有迁移到油和水界面的趋势。这项研究为功能性乳液分析提供了一种新颖的方法，可为将来设计稳定和可控的乳液体系释放提供基础。