姜黄素-淀粉纳米微胶囊的研制及其抗氧化研究

Preparation of curcumin-starch nano-microcapsules and its antioxidant research

为提高有益的生物活性疏水小分子的生物利用度,采用纳米液滴控制法制备对疏水性物质姜黄素具有良好吸附性能的淀粉纳米粒子,姜黄素在淀粉纳米颗粒的糊化-老化过程中被负载形成以淀粉纳米粒为外壳的微胶囊形式的核壳结构。通过微观结构、X射线衍射和傅里叶变换红外光谱探讨了淀粉纳米粒子和姜黄素的结合方式,并应用于食品包装材料。结果表明:淀粉纳米颗粒的平均粒径为(200±40) nm,呈圆形或椭圆形,复合物属于V形结晶构型,姜黄素与淀粉纳米粒子的络合方式是通过氢键和疏水相互作用。淀粉纳米粒子对姜黄素的负载率达到75.5 mg/g, DPPH自由基清除率达到59.3%。淀粉纳米粒子具有良好的生物相容性,不仅提高了姜黄素的稳定性,而且有利于人体的吸收和利用,负载姜黄素后添加到薄膜材料中其具有作为抗氧化包装的潜力。

Most biologically active small molecules or nutrients have poor water solubility, making it difficult for the human body to absorb and utilize them. Meanwhile, these small molecules are easily oxidized or decomposed by external factors(light, heat, extrusion vibration, strong acid/base, etc.) during the transportation, preservation or processing of these small molecules. Therefore, it is necessary to achieve high-efficiency loading and stable release of hydrophobic active molecules, as well as good biocompatibility to the human body. The drug-loaded microcapsules not only improve the absorption and availability of hydrophobic small molecules, but also can exert their characteristics in packaging materials. In this study, curcumin was used as a representative hydrophobic active molecule as a model drug, and starch nanoparticles were used to prepare curcumin-loaded microcapsules.The physicochemical properties(molecular weight distribution, microstructure, particle size distribution and crystalline configuration) of starch nanoparticles were studied by using ultrasonic-assisted emulsification to prepare starch nanoparticles with controllable particle size. On this basis, curcumin was successfully loaded into the inner cavity of starch nanoparticles by solvent exchange method, and the loading amount of curcumin by starch nanoparticles was determined. The position of curcumin in the microcapsule system was detected by fluorescence localization method combined with laser confocal microscopy, and its thermal stability, crystalline configuration, binding mode, and free radical scavenging ability in vitro were measured. In order to improve the bioavailability of bioactive hydrophobic small molecules and the stability of curcumin during the processing of starch-based degradable active films, starch nanoparticles were prepared by ultrasonic-assisted emulsion droplet control method using debranched waxy corn starch as raw material. Curcumin was loaded and added to starch-based degradable films for active bread packaging applications. The main conclusions were as follows: Starch nanoparticles were formed from short amylose with a polymerization degree of 12 by spontaneously forming a left-handed helical structure. The particle size distribution was 56-254 nm, the appearance was round or oval, and the interior showed a hollow structure. Subsequently, curcumin was loaded into the interior of the starch nanoparticles by the solvent exchange method to form microcapsules, and the V-shaped crystalline structure was formed through hydrogen bonding and hydrophobic interaction. Meanwhile, the microcapsule structure had good thermal stability, which increased the stable temperature of curcumin from 200 ℃ to 250 ℃. In addition, the loading rate of curcumin by starch nanoparticles reached 75.5 mg/g, and the free radical scavenging efficiency reached 59.3%. Therefore, starch nanoparticles had good biocompatibility, improved the stability and solubility of curcumin, and could improve the absorption and utilization of human body.