Research on Fatty Acid Demulsification Technology and Mechanism of Peanut OBs

In this study, different fatty acids were used for demulsification of peanut oil bodies (OBs) extracted by aqueous enzymatic method. Demulsification process was optimized, and mechanism of fatty acid demulsification was studied. By screening of fatty acids and optimizing demulsification process, octanoic acid had the best demulsification effect (98.23%). OBs maintained stability through electrostatic repulsion and steric hindrance. Octanoic acid adjusted pH to isoelectric point (pI) of OBs proteins, which made electrostatic charge on OBs surface was almost zero, reduced electrostatic repulsion, resulted oil droplets aggregation and fusion. With the increase of demulsification time, contents of α-helix and β-folding gradually reduced, contents of β-turning and random coil gradually increased, the maximum fluorescence peak of OBs proteins had obvious redshift, showing internal space conformation of proteins was destroyed and protein molecules were unfolded. Interfacial membrane structure of OBs was destroyed, resulted proteins and phospholipid were no longer evenly distributed on OBs surface. OBs could not maintain original stable form, aggregation and fusion occurred between oil droplets, achieving demulsification. Results of this study suggest that octanoic acid demulsify of peanut OBs was high efficiency, which provided theoretical basis for realizing industrialization of extracting peanut oil by aqueous enzymatic method.