Preparation of Water Extract of Sesame Seeds
Sesame seeds (100 g) were washed by tap water to remove impurities and soaked in deionized (DI) water at 4 °C for 16 h. The soaked seeds were rubbed with hands and put into 20% sucrose solution to float the dehulled seeds, which were collected and washed three times with precooled (4 °C) DI water. Precooled DI water was added to the total weight of 500 g, and ground for 1.5 min by a Waring blender (15000 rpm; BLST409B-073, Oster; Dongguan, Guangdong, China), and filtered through cheese cloth to obtain water extract 1 and okara 1. 200 g of precooled DI water was added into okara 1, and ground for 1 min. This mixture was filtered to obtain water extract 2 and okara 2. To okara 2, the above procedure was repeated to obtain water extract 3 and okara 3. The water extract 1–3 were mixed to get the water extract of sesame seeds. The lipid contents in sesame seeds and water extract were determined by the chloroform/methanol (2/1, v/v) method, and it was calculated that approximately 92% of total lipids in sesame seeds were recovered in the water extract.