Evaluation of starch propionate as emulsion stabiliser in comparison with octenylsuccinate starch

Starch propionate (SP) with a degree of substitution (DS) of 0.21 was produced and its ability to stabilise emulsion was studied and compared with a commercial octenylsuccinate (OSA) starch (DS 0.03). The intrinsic viscosity values of SP and OSA were 0.9018 and 0.2514 (100 mL/g), respectively. Three different concentrations of SP and OSA at 12, 14 and 16 g/100 g of water phase and two different concentrations of oil at 35 and 45 g/100 g of water and oil phase were evaluated. Rheological properties, particle size and creaming index were assessed. Both SP and OSA emulsions produced shear thinning curve. Increase in concentration of starch stabilisers led to the increase in yield stress and apparent viscosity. SP emulsions demonstrated a significantly higher yield stress and apparent viscosity compared to OSA emulsions. SP emulsion showed G' > G values but OSA emulsions exhibited G > G' throughout the whole frequency range. As modified starch concentration increased, mean droplet diameter (d(32)) decreased. All SP emulsions were stable when stored at room temperature for 14 days. SP has great potential to be used in the preparation of cream-type emulsion such as mayonnaise, dermatological creams and cosmetic products.