A new application with characterized oil-in-water-in-oil double emulsions: Gelatin-xanthan gum complexes for the edible oil industry

Abstract

A novel oil-in-water-in-oil (O1/W/O2) double emulsion (DE) system was successfully created to decrease the saturated fat content. DEs stabilized with gelatin (GL), xanthan gum (XG), and solid fat crystals were generated using a two-stage emulsification process. Primary emulsions (PEs) containing 60 g/100 g and 20 g/100 g sunflower oil (SFO) were prepared with constant GL (at 1 g/100 g) and XG (at 0.6 g/100 g and 1.4 g/100 g) of the total emulsion, respectively. DEs at constant water concentrations containing SFO at 30, 38.3, 46.7, and 55 g/100 g and different water concentrations at 30, 40, 45, and 60 g/100 g were examined. The DE microstructure showed that SFO was encapsulated in internal water droplets, which were stabilized by interfacial accumulation of fat crystals. The hardness value of the DEs decreased from 13.40 to 3.42 N with increasing SFO. Amplitude and frequency sweep tests revealed a weak gel structure and elastic behavior of DEs. In addition, a decrease in gel stiffness was observed with an increase in SFO and water content. The results of the present study effectively demonstrated a new approach applicable for the edible oil industry, formulating O1/W/O2 DEs using a natural emulsifier (GL) and a stabilizer (XG).