An efficient method of ultrasound-assisted aqueous enzymatic extraction of corn germ oil was established, and its quality and antioxidant activity were studied. The optimum auxiliary extraction conditions with ultrasound were as follows: the ultrasonic treatment time was 20 minutes, and the ultrasonic temperature was 40°C. The corn germ oil extracted by the aqueous enzymatic method had better quality indexes in comparison with that exacted by the solvent. The fatty acid compositions of corn germ that was oil-extracted by two kinds of methods had almost no significant differences. The tea polyphenols (TP) exhibited remarkable antioxidant effects on corn germ oil during a storage stability test. Meanwhile, we focused on the antioxidant activity of corn germ oil, and the results showed that corn germ oil could effectively scavenge 1,1-diphenyl-2-picrylhydrazyl(DPPH), hydroxyl radical and superoxide anion free radicals. Thus, corn germ oil is a kind of functional oil with excellent antioxidant activity and could be used as a free radical scavenger in the food or other industries.
Keywords: antioxidant activity; aqueous enzymatic extraction; corn germ oil; quality; ultrasound.