Preparation method of functional fatty acid

The invention discloses a preparation method of functional fatty acid, which comprises the following steps: dissolving wool fat in an alcohol-water solution, adding excessive strong base, heating and saponifying to obtain a saponified solution; adjusting the pH value of the saponification liquid to be neutral or alkalescent by using a strong acid aqueous solution, adding water to reduce the alcohol concentration, and then adding an extraction solvent for extraction; continuing to add a demulsifier for extraction, then separating extract liquor, removing an organic phase, and retaining a water phase; adjusting the pH value of the water phase to strong acidity by using a strong acid water solution, adding an extraction solvent, heating and extracting, retaining an upper organic phase, and removing the extraction solvent by rotary evaporation to obtain the functional fatty acid. According to the method, the demulsifier extraction method is used for preparing and enriching the branched-chain fatty acid in the woo