Bitter orange oil incorporated into chitosan nanoparticles: Preparation, characterization and their potential application on antioxidant and antimicrobial characteristics of white button mushroom

Citrus aurantium essential oil (CAEO) at different concentrations was incorporated into chitosan nanoparticles (CSNPs) by an ionic gelation technique to enhance the antioxidant activity and control of the microbial population of Agaricus bisporus during cold storage. The physicochemical properties of nanoparticles were investigated by high resolution transmission electron microscopy (HRTEM), FTIR, and dynamic light scattering (DLS). The synthesized nanoparticles showed spherical shape with an average size of 20-60 nm. The encapsulation efficiency and loading capacity of CAEO-CSNPs were between 4.51-15.33% and 2.51-5.89%, respectively. The release of CAEO from CSNPs followed Fickian diffusion model. In comparison with control treatment, a lower microbial count, decrease in POD activity and higher activity of the antioxidant enzymes, glutathione reductase (GR) and ascorbate peroxidase (APX), were observed in mushrooms packed with CAEO-CSNPs (P < 0.01). These results revealed the promising role of CSNPs as a delivery system for CAEO to improve microbial safety and antioxidant enzymes activity of white button mushroom.