Abstract: This study aimed to explore the feasibility of using whey protein and octenyl succinic anhydride (OSA) modified starch in combination to improve the physical stability of nanoemulsions. Nanoemulsions stabilized by whey protein and whey protein-OSA modified starch (weight ratio was 7∶3) were prepared by ultrasonic homogenization. The effects of pH, ionic strength and heat treatment on the stability of nanoemulsions were investigated. The results showed that at pH=4, the particle size of nanoemulsion prepared with whey protein increased significantly to 2 100 nm, while the particle size of nanoemulsion prepared with whey protein-OSA modified starch was only 280 nm. This indicated that OSA modified starch was effective in attenuating droplet aggregation of whey protein-coated nanoemulsion. Moreover, the particle size of the whey protein-OSA modified starch prepared nanoemulsion did not change significantly when the concentration of Na+ was less than 0.6 mol/L and at 40-80 ℃. This study shows that OSA modified starch is expected to expand the use of whey protein stabilized nanoemulsions in acidic foods.
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