In order to investigate the influence of concentration of AP to the storage stability and fatty acid accessibility， different concentration of AP (0-5 g/L) was applied as the stabilizer. The storage stability was determined by dynamic light scattering and visual stability. Meanwhile， the influence of in vitro simulated digestion on the protein structure， emulsion structure and fatty acid accessibility was also investigated using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis， dynamic light scatting technologies， confocal laser scanning microscopy， the release of fatty acid and gas chromatography. The results show that the storage stability of SOB and POB is highly dependent on the AP concentration when the AP concentration is less than 3 g/L. The storage stability of emulsions is significantly improved when the AP concentration is higher than 1.5 g/L， this is due to the decreasing of aggregation and increasing of surface charge values. When the AP concentration is between 3-5 g/L， the influence of pectin to the stability of emulsion reaches a balance statue. During in vitro simulated digestion， the activity of pepsin can be inhibited by adding AP， peptides below 15 ku is formed during the testing. The ζ-potentials of emulsion significantly reduces due to the formation of negatively charged peptides， increasing of bile salts， and releasing of free fatty acids. In the testing， the free fatty acid accessibility decreases by 3.3% with 1.5 g/L of AP compared with OBs without AP， this is due the inhibits of pepsin during the hydrolysis of OBs proteins and the controlling of SOB-AP size. However， the free fatty acid accessibility increases by 33.8% with POB. This is due to the bigger hydrolyzed area of trypsin in POB-AP.