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.