Yellow soybean hulls
Grinding: around 18 mesh
Acid digestion (pH 1.5-2.0): adjusted by 2N HCl: 60 C for 2hr
Washed by H2O to pH 6.8-7.0
Autoclave: 121 C, 15 lbs. pressure for 10 min
Dehydration: 60 C air drying until 10% final moisture content
Grinding: around 70mesh
Dewatering: 5000g, 10 min centrifugation
Alkaline digestion (pH 10-11): adjusted by 2N KOH: 60 C for 2hr
Washed by H2O to pH 7.0-7.2
Dewatering: 5000g, 10 min centrifugation
Dietary fiber powder