Microencapsulation of sacha inchi oil using emulsion-based delivery systems

Abstract

In this study, sacha inchi oil (SIO) was microencapsulated by emulsion-based systems using ovalbumin (Ova), pectin (Pec), and xanthan gum (XG), followed by freeze-drying. The microencapsulation was confirmed using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The stability of omega-3 in SIO alone as well as in microencapsulated SIO was assessed by nuclear magnetic resonance (1H NMR) spectroscopy after human gastric simulation (HGS). The SEM results revealed distinct structures for the two types of microcapsules. The thermograms showed that the thermal resistance was increased in the microencapsulated SIO, indicating that the emulsion-based system may be a way to protect the omega-3 in the SIO. In addition, the microencapsulation conferred an increased crystallinity degree, indicating a higher structural organization. Moreover, this method did not affect the stability of SIO, as confirmed by 1H NMR. The release of omega-3 acyl units from the SIO was correlated with the decrease of the methynic proton (sn, 2 position) of triacylglycerol (TAG). In contrast, the increase of 1,3-diglycerides was negatively correlated with the decrease of glyceryl groups (sn, 1,3 positions). The HGS conditions did not significantly alter the stability of the omega-3 of SIO over 180min. The SIO-Ova microcapsules had a similar behavior to the SIO, and the presence of Ova was not enough to prevent the decrease of omega-3 content over 180min. The SIO-Ova-Pec and SIO-Ova-XG microcapsules were shown to protect the omega-3 content effectively. In conclusion, the microcapsules developed in this study can be used to transport nutraceutical compounds because they are resistant to the human gastric conditions tested in vitro.