Synthesis of curcumin-loaded shellac nanoparticles via co-precipitation in a rotating packed bed for food engineering

Practical application of versatile nanomaterials to food engineering is desirable. In this study, highly encapsulated curcumin-loaded shellac (Cur@Lac) nanoparticles are efficiently prepared via a rotating packed bed (RPB). In this modified co-precipitation process, the morphology of Cur@Lac nanoparticles is systematically investigated under experimental parameters involving the high-gravity level, the volume of antisolvent and the concentration of shellac. By virtue of the highly structured polymeric ester matrices of shellac and adequate supersaturation brought from RPB on a microscale, the obtained Cur@Lac nanoparticles with uniform size exhibit high encapsulation efficiency of over 96%. After 2 months of storage at room temperature, the aqueous Cur@Lac nanodispersions exhibit long-term stability with no agglomeration or sedimentation, and the final retention rate of curcumin was over 85%. Colored drinks of fruit syrup (pH = 4.0), fruit soda (pH = 6.0), and soda water (pH = 8.3) are prepared by using the Cur@Lac as the colorant, which possessed orange-yellow color. The nanocomposites of alkali-sensitive indicators based on cellulose paper and gelatin film demonstrated in the work show promising application value for sensing of alkaline solution and gas of perishable food.