Encapsulation of extract from winery industry residue using the supercritical anti-solvent technique

Abstract

Grape pomace (seed, skin and stem) is a winery byproduct with high levels of biologically active compounds, such as antioxidants and antimicrobials, that could be converted into high added-value products. Since these components are easily degraded by oxygen, light and high temperature exposure, stabilization is important, for instance, by a microencapsulation process. Therefore, the objective of this study was to investigate the influence on the particle characteristics of the operational conditions applied in the Supercritical Anti-Solvent (SAS) process for the co-precipitation of grape pomace extract and poly(-lactic-coglycolic acid) (PLGA). The morphology and size of the particles formed, their stability and thermal profile were evaluated, and also the co-precipitation efficiency. The conditions studied allowed the production of microparticles with spherical shape for all operational conditions, with estimated particle size between 4 ± 2 and 11 ± 5 μm, and very good co-precipitation efficiencies (up to 94.4 ± 0.6%). The co-precipitated extract presented higher stability compared to the crude extract, indicating the effectiveness of the co-precipitation process and coating material against degradation processes.