Fabrication, characterization and stability of oil in water nano-emulsions produced by apricot gum-pectin complexes

Abstract

In this study, the effects of apricot gum-apple pectin (AG/pectin) complex as an emulsifier and stabilizer on the sunflower oil in water nano-emulsion parameters including droplet size, zeta-potential, and the creaming index was investigated. The first independent variables were AG concentration in AG/pectin complex. Applying a 21.4 (w/w) ratio of AG/pectin resulted in nano-emulsions with the highest creaming stability, and most stable droplet size and zeta-potential during 10days storage. Then, droplet size, zeta-potential, and stability of this emulsion (21.4 (w/w) ratio) were further investigated under environmental and process stresses including thermal processing, sonication, and pH changes. Emulsions with smaller droplet sizes, higher zeta-potentials, and higher creaming stability were obtained by applying sonication treatment. A 10min ultrasound treatment with the amplitude of 25% was proposed as the optimum conditions for ultra-sonication. Also, emulsions prepared by AG/pectin ratio of 21.4 (w/w) showed best stability at 60°C and pH of 2.