Optimization and characterization of lemon essential oil entrapped from chitosan/cellulose nanocrystals microcapsules

Abstract The purpose of this study is to prepare lemon essential oil (LEO) microcapsules by ionic gelation method using chitosan (CS) and cellulose nanocrystals (CNC) as the wall material. The influence of the concentration of CS and CNC and the pH of CS solution on the encapsulation efficiency (EE) of microcapsules was studied. Taking the EE as an indicator, and according to the single‐factor test results, a three‐factor three‐level response surface methodology was designed. The best process conditions of CS/CNC‐LEO microcapsules to get the maximum EE of 89.98% were as follows: pH of CS was 3.44, and the concentration of CS, CNC were 2, 3.52 g/L. The microcapsules prepared under these conditions were smooth and rounded spherical. The diameters of unembedded and embedded LEO microcapsules ranged from 541.2–732.9 to 1014.5–1528.7 nm, respectively. Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis were used to analyze the characteristics of the microcapsules. There were two periods in vitro release studies of CS/CNC‐LEO microcapsules: sudden release and slow release of essential oils.