Sodium caseinate stabilized clove oil nanoemulsion: Physicochemical properties

In the present study, Clove oil nanoemulsions were prepared using sodium caseinate (NaCas-5%) & pectin (0.1%) as coating material by high speed homogenization. Mean particle size, poly dispersity index (PDI) and zeta potential of most stable nanoemulsion was172.1 ± 4.39 nm, 0.152 ± 0.01 and −37 ± 1.93 mV, respectively with an encapsulation efficiency of 88%. Nanoemulsion was stable at all food processing conditions that generally encountered during processing except pH 3.0–5.0. Droplet diameter was increased with increase in storage time from 0th day (172.1 ± 4.39 nm) to 20th day (415.3 ± 23.38 nm) at 25 °C. Scanning electron micrographs showed spherical nanoparticles with slight adherence whereas transmission electron micrographs confirmed the morphology through discrete spherical droplets with defined boundaries of core and coating material. Our results suggest the possibility of clove oil nanoemulsion as delivery system for antimicrobial bioactive substances in food preservation with a green image.