The combined extraction was performed in the similar proce-dure as protein extraction, only used full-fat kernel as the extracted material. Extraction was performed for 1 or 6 h. For experiments with native or inactivated protease, 5% protease volume per weight protein was added before extraction. Inactivation of protease was performed by incubation at 90 ◦ C for 10 min prior to the addition.