Annatto Polymeric Microparticles: Natural Product Encapsulation by the Emulsion–Solvent Evaporation Method

摘要

In this experiment, the extract from annatto seeds was encapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) particles by the emulsion–solvent evaporation method. The particles were washed and centrifuged to remove excess stabilizer and then freeze-dried. The main compound of annatto seeds, bixin, has antioxidant properties as well as an orange-red color. These features make annatto extract useful in the cosmetic and food industries. As an oxidant compound, bixin can readily undergo degradation. Therefore, the encapsulation of this natural product is an option to promote higher stability. In addition, a polymeric matrix can promote a sustained release of bixin molecules. The polymer employed, PHBV, is a low-cost and biodegradable material. The emulsion–evaporation method is a technique that can be used to encapsulate lipophilic molecules in a polymeric matrix. The experimental procedure involves many important concepts of colloidal chemistry such as surface tension, emulsion stability, and Ostwald ripening, among others.