Nanoencapsulation of lemon essential oil in Chitosan-Hicap system. Part 1: Study on its physical and structural characteristics

Lemon essential oils (LEOs) as a bioactive compound with health beneficial potential are used as safe additives in foods, medicine and nutritional supplements. However, it is a chemical compound which is sensitive to light, thermal condition and oxidation. To overcome these challenge encapsulation could be an adequate technique to protect them from degradation and evaporation. In this study, nanocapsules based on chitosan (CS) and modified starch (Hicap) with LEOs as an active ingredient was prepared by freeze-drying. The produced nanocapsules were characterized by their structural and physicochemical properties. It was found that nanocapsules produced by using CS: Hi-cap (1.5%:8.5%) clearly showed the highest encapsulation efficiency (85.44%) and Zeta potential value (+44.23 mV). In vitro release studies demonstrated a prolonged release of the samples with larger CS ratio. Most nanocapsules sizes ranged from 339.3 to 553.3 nm. The obtained nanocapsules showed a rough surface without the spherical shape as represented by Scanning electron microscopy images. Differential scanning calorimetry (DSC) thermogram and Fourier transform infrared (FTIR) spectroscopy techniques confirmed the success of LEOs encapsulation. The desirable physicochemical properties and thermal stability specified that such nanocapsules have promising application in delivery of LEOs in medicine and food industries.