Encapsulation of neem (Azadirachta indica) seed oil in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by SFEE technique

Neem seed oil has several compounds, that need to be protected of light, oxygen and temperature to preserve their activity. The objective of this work was to encapsulate neem seed oil in PHBV by Supercritical Fluid Extraction of Emulsions technique. PHBV was characterized by NMR, SEC, DSC and TG. Emulsions were characterized by DLS to evaluate droplet size and emulsion stability. Encapsulation of neem seed oil into PHBV particles was verified by UV spectroscopy. Particles obtained after SFEE process were characterized by DLS and SEM. Through NMR analysis it was possible to quantify 82% hydroxybutyrate and 8% hydroxyvalerate. Particles presented two melting peaks, at 141 degrees C (hydroxyvalerate moiety) and at 170 degrees C (hydroxyvalerate moiety). Emulsion droplets presented an average size of 463 nm and were stable for at least 90 min. Average particle size after the SFEE was 228 nm. Encapsulation efficiency of neem oil into PHBV was between 8.58 and 12.79%. Results showed that stable emulsions are generated and suggested that SFEE technique is a reliable methodology for encapsulation of neem oil using PHBV as biopolymer. (C) 2019 Elsevier By. All rights reserved.