School of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, China.
National Research Center for Geoanalysis, Beijing 100037, China.
Food Funct. 2022 Apr 20;13(8):4734-4747. doi: 10.1039/d1fo03500b.
This study aimed to prepare fish oil microcapsules by freeze-drying an emulsion co-stabilized by rice bran protein fibrils (RBPFs) and xanthan gum (XG) to improve the oxidation stability and controlled release effect. Emulsions stabilized either solely by RBPFs or unfibrillated rice bran protein (RBP) or by a combination of RBP and XG were also fabricated as microcapsule templates for comparison. The rheological properties, particle size, and zeta potential of the emulsions were examined. In addition, the characteristics of the fish oil microcapsules such as surface oil content, encapsulation efficiency, water activity, moisture content, morphological structure, oxidation stability, and digestive performance were also assessed. The rheological properties revealed that the addition of XG increased the storage modulus of the emulsion and reduced the loss modulus and apparent viscosity. At shear rates of 0-100 s, the fish oil emulsion did not exhibit any gel properties or shear thinning. Fibrillation increased the particle size of the fish oil emulsion, whereas adding XG reduced the droplet size. The combination of RBP fibrillation and XG addition provided the highest encapsulation efficiency for fish oil. Fibrillation reduced the water activity and moisture content of the fish oil microcapsules. The anisotropy of the fibrils and the high viscosity of XG produced a layer of wrapping on the continuous heterogeneous surface of the freeze-dried powder particles. RBPF/XG microcapsules stored at 45 °C for 1 month had the lowest peroxide value and thiobarbituric acid value, the lowest surface oil content, and the lightest yellowness. These results suggest that the combination of RBPFs and XG provides better encapsulation and protective effects for fish oil microcapsules. Upon simulated digestion, the microcapsules containing XG and RBPFs exhibited a more favorable controlled release of free fatty acids. These findings indicate that microcapsules formed from emulsions co-stabilized by XG and RBPFs are suitable for encapsulating fish oil in functional foods.
本研究旨在通过冷冻干燥由米糠蛋白纤维（RBPFs）和黄原胶（XG）共同稳定的乳液来制备鱼油微胶囊，以提高氧化稳定性和控制释放效果。还制备了仅由 RBPFs 或未纤维化米糠蛋白（RBP）或 RBP 和 XG 组合稳定的乳液作为微胶囊模板进行比较。考察了乳液的流变性能、粒径和zeta 电位。此外，还评估了鱼油微胶囊的特性，如表面油含量、包封效率、水活度、水分含量、形态结构、氧化稳定性和消化性能。流变性能表明，添加 XG 增加了乳液的储能模量，降低了损耗模量和表观粘度。在剪切速率为 0-100 s 时，鱼油乳液没有表现出任何凝胶特性或剪切变稀。纤维化增加了鱼油乳液的粒径，而添加 XG 则减小了液滴尺寸。RBP 纤维化和添加 XG 的组合为鱼油提供了最高的包封效率。纤维化降低了鱼油微胶囊的水活度和水分含量。纤维的各向异性和 XG 的高粘度在冷冻干燥粉末颗粒的连续非均相表面上产生了一层包裹物。在 45°C 下储存 1 个月的 RBPF/XG 微胶囊具有最低的过氧化物值和硫代巴比妥酸值、最低的表面油含量和最浅的黄色。这些结果表明，RBPFs 和 XG 的组合为鱼油微胶囊提供了更好的包封和保护效果。在模拟消化过程中，含有 XG 和 RBPFs 的微胶囊表现出更有利的游离脂肪酸的控制释放。这些发现表明，由 XG 和 RBPFs 共同稳定的乳液形成的微胶囊适合在功能性食品中封装鱼油。
