Ascorbic acid encapsulation in a glassy carbohydrate matrix via hot melt extrusion: Preparation and characterization

Abstract Hot melt extrusion technology using a twin-screw extruder was employed to obtain maltodextrin, maltodextrin-gum arabic and maltodextrin-trehalose based glassy extrudates containing ascorbic acid (dispersed phase). Ascorbic acid payload of all three formulations was more than 15.67 g/100 g extrudates while the ascorbic acid yield was above 97%. The glass transition temperature (Tg) of all extrudates was above 40 °C. The expansion ratio of the extrudates and Tg reduced due to the incorporation of trehalose and gum arabic to maltodextrins, respectively. The results of Scanning Electron Microscopy, X-ray diffraction and Fourier-transform Infrared Spectroscopy confirmed that the formulated feed material turned into a glassy state, whereas, ascorbic acid was uniformly dispersed throughout the glassy matrix. Extruded formulations showed a steady dissolution rate, therefore, having a role in controlling the dissolution rate of ascorbic acid.摘要：本研究采用双螺杆挤出机（twin-screw extruder）的热熔挤出技术，制备了以麦芽糊精、麦芽糊精-阿拉伯胶、麦芽糊精-海藻糖为载体的玻璃态挤出物，其中包埋有作为分散相的抗坏血酸（ascorbic acid）。三种配方的抗坏血酸载量均超过15.67 g/100 g挤出物，而抗坏血酸的收率均高于97%。所有挤出物的玻璃化转变温度（glass transition temperature，Tg）均高于40 ℃。向麦芽糊精中添加海藻糖会降低挤出物的膨胀率，而加入阿拉伯胶则会使其玻璃化转变温度下降。扫描电子显微镜（Scanning Electron Microscopy，SEM）、X射线衍射（X-ray diffraction，XRD）与傅里叶变换红外光谱（Fourier-transform Infrared Spectroscopy，FTIR）的检测结果证实，所配制的进料原料已转变为玻璃态，且抗坏血酸均匀分散于整个玻璃态基质中。经挤出制备的配方具有稳定的溶出速率，因此可用于调控抗坏血酸的溶出行为。