Barrier properties and storage stability of edible coatings prepared with electrospraying

Electrospraying is a novel technique for the application of coating to foods. In this study, thin lipid-based coatings were prepared by electrospraying on model surface and evaluated for their moisture barrier functionality. Sunflower oil and chocolate based coating materials were electrosprayed at elevated temperature (60 °C) using a multiple nozzle system. Sunflower oil coated the sides and top surface of the target surfaces, while chocolate based material deposited primarily on the top surface. In chocolate based coatings, larger droplet size and related lower charge to mass ratio explained the limited “wrap-around effect”. Sunflower oil based coating penetrated into the target surfaces, which could be reduced by the addition of stearic acid (up to 0.15 g/g). However, this addition resulted in crystallization and crack formation during storage, and ultimately reduced barrier functionality. Conversely, chocolate-based material produced thicker coatings (up to 0.3 mm), which were more stable during storage and exhibited enhanced barrier properties.