Preparation and properties of walnut oil microcapsules

This study uses spray drying to prepare walnut oil (WO) microcapsules with microcrystalline cellulose (MCC) and β-cyclodextrin (β-CD) to mitigate the oxidation of WO and prepare for further applications of the microcapsules. The successful encapsulation of WO was confirmed through analysis with a scanning electron microscope (SEM), fourier-transformed infrared spectrometer (FTIR), and x-ray diffraction (XRD), achieving an encapsulation efficiency (EE) of 80.54% and a loading capacity (LC) of 53.87%, with interactions or non-covalent bonds between WO and the wall materials. The powder has an average particle size of 1553.17 nm, 2.85% moisture, 90.62% solubility, and good flowability. After a 7-day accelerated test at 60°C, the microcapsules showed a PV of 4.02 meq/kg and AV of 0.63 mg/g, lower than the walnut oil's PV of 5.35 meq/kg and AV of 0.81 mg/g. The results indicate that the microcapsules have good properties and a reduced degree of oxidation compared to WO. • Microcrystalline cellulose and β-cyclodextrin were used as mixed wall materials; • This study significantly enhances the loading capacity of walnut oil microcapsules; • The oxidation level of microcapsules was effectively reduced compared to walnut oil.