Nanoencapsulation of Royal Jelly in Chitosan Nanocomplex through Ionic Gelation: Optimization and Characterization

Abstract Royal jelly is highly prone to spoilage and quality degradation when stored under unsuitable conditions or when the cold chain is disrupted, leading to a loss of functional and commercial value. Moreover, its sharp and pungent taste and odor, mainly attributed to fatty acids, limit consumer acceptance. Nanoencapsulation has emerged as an effective strategy to address these challenges. In the present study, royal jelly was nanoencapsulated using the ionic gelation method, and the effects of chitosan solution pH (3, 4.5, and 6), chitosan concentration (0.5, 1, and 1.5 g/100 mL), and syringe pump flow rate (0.5, 1, and 1.5 mL/min) on the physicochemical and bioactive properties of royal jelly–loaded chitosan nanoparticles were investigated. A Box–Behnken experimental design was employed to determine the optimal process conditions. The developed models for the dependent variables were statistically significant ( P < 0.05). ANOVA revealed that chitosan concentration and solution pH had a more pronounced effect on the dependent variables compared to the syringe pump flow rate. The optimal nanoencapsulation conditions, with a desirability value of 0.809, were determined to be pH 3.64, a chitosan concentration of 1.31%, and a syringe pump flow rate of 0.5 mL/min. Under these conditions, encapsulation efficiency, zeta potential, particle size, total phenolic content, and antioxidant activity were measured as 74.18%, 33.42 mV, 369.77 nm, 69.75 mg GAE/100 g, and 18.46%, respectively. FT-IR analysis confirmed successful nanoencapsulation through interactions between royal jelly and chitosan functional groups, resulting in smooth, clustered spherical nanoparticles.