Raspberry-liked Pickering emulsions based inulin microparticles for enhanced antibacterial performance of essential oils

Pickering emulsions seem to be an effective strategy for encapsulation and stabilization of essential oils. In this work, a novel raspberry-liked Pickering emulsion (RPE) loading Mosla chinensis 'Jiangxiangru' essential oil (MJO) was successfully engineered by using ethyl lauroyl arginate (ELA) decorated nanosilica (ELA-NS) as particles emulsifier. And the ELA-NS-stabilized MJO Pickering emulsion (MJO-RPE) was further prepared into inulin-based microparticles (MJO-RPE-IMP) by spray-drying, using inulin as matrix formers. The concentration of ELA-NS could affect the formation and stabilization of MJO-RPE, and the colloidal behavior of ELA-NS could be modulated at the interfaces with concentration of ELA, thus providing unique role on stabilization of MJO-RPE. The results indicated that the MJO-RPE stabilized ELA-NS with 2 % NS modified by 0.1 % ELA had long-term stability. MJO-RPE exhibited a raspberry-liked morphology on the surface, attributed to ELA-NS covered in the droplet surface. The inulin-based matrix formers could effectively prevent MJO-RPE from agglomeration or destruction during spray-drying, and 100 % concentration of inulin based microparticles formed large composite particles with high loading capacity (98.54 ± 1.11 %) and exhibited superior thermal stability and redispersibility of MJO-RPE. The MJO-RPE exhibited strong antibacterial efficacy against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa), owing to the adhesion to bacterial membrane dependent on the raspberry-liked surface of MJO-RPE, whose minimum inhibitory concentration (MIC) of the above three bacteria were (0.3, 0.45, and 1.2 μL/mL), respectively, lower than those (0.45, 0.6 and 1.2 μL/mL) of MJO. Therefore, the Pickering emulsion composite microparticles seemed to be a promising strategy for enhancing the stability and antibacterial activity of MJO.