Study on the Extraction of Soybean Soluble Dietary Fiber

The extraction technology of soluble dietary fiber from soybean dregs was investigated under room pressure and by pressurized pre-treatment. It was found that, for the extraction under room pressure, the best concentration of sodium hexameta phosphate solution, pH value, ratio of solid to liquid, temperature and extraction time were 2%, 6.5, 1:30, 60 ℃ and 2h, respectively. For the extraction with pressurized pre-treatment, the optimal temperature, pH value and extraction time were 120 ℃, 5.7 and 3.5 h, respectively. On the basis of this work, a pilot-scale production was finished by membrane separation technology and spray dryer. The production cost decreased greatly and quality of SDF was better. This made it suitable for industrialization. The best material for production of SDF was the soybean meal which protein was extracted ahead; the extraction rate of SDF was more than 43.0% of the material.