The invention relates to a method for extracting
limonin and nomilin. The method comprises the following steps:
degreasing a
raw material, and then subjecting the degreased
raw material to
enzymatic hydrolysis with a wheat koji compound
enzyme solution; removing supernatant liquid to obtain an
enzymatic hydrolysis base material; adding a
sodium salicylate solution for extraction, and separating aliquid extract; adjusting the pH value of the extract to 4.6-5.0, loading a supernatant onto
macroporous resin, carrying out
elution by using an
ethanol solution with a concentration of 20-25% so as to remove impurities, then carrying out
elution by using an
ethanol solution with a concentration of 85-90%, collecting eluates, recovering the
ethanol, and carrying out
drying to obtain an extract A;dissolving the obtained extract A with a
mixed solution of
dichloromethane and
isopropyl alcohol by heating, carrying out filtering to remove insoluble matters, and then successively carrying out cooling and crystallized so as to obtain
limonin crystals; and subjecting mother liquid to pressure-reduced
evaporation to
dryness so as to obtain an extract B, dissolving the obtained extract B with a
mixed solution of
ethyl acetate and ethanol by heating, carrying out filtering to remove insoluble matters, and then successively carrying out cooling and crystallized so as to obtain nomilin crystals.The extraction method of the invention is low in cost and high in yield and product purity, and reduces environmental
pollution.