1. Preparation of isoflavones enriched soy protein isolate from defatted soy hypocotyls by supercritical CO2
- Author
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Yu, Jun, Liu, Yuan-Fa, Qiu, Ai-Yong, and Wang, Xing-Guo
- Subjects
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ISOFLAVONES , *SOY proteins , *BENZOPYRANS , *PLANT proteins - Abstract
Abstract: Soy hypocotyls, the byproduct from soy protein industry, rich in isoflavones, was attempted to develop into a value-added functional food, soy protein isolate (SPI). Soy hypocotyls were defatted by supercritical CO2 (SC-CO2) under the following conditions as 35MPa, 2h, 45°C with a constant flow rate of CO2 at 5l/min, fed from the bottom of the extraction vessel. Via extraction, the oil contents were lowered from 10.5g/100g in original soy hypocotyls to 0.2g/100g in defatted soy hypocotyls (DSH) with a Protein Dispersibility Index (PDI) value of 91.2 that contained about 2.18g/100g of isoflavones and 63.6g/100g of proteins. SPI was then extracted from DSH under the optimized conditions including: the pH of water solution at 6, the ratio of DSH to water solution as 1:10 and the extraction temperature at 30°C with the extraction time of 30min. The freeze-dried SPI contained 92.46g/100g of the proteins and 640mg/100g of isoflavones, where the three major β-glycosides, glycitin, daidzin and genistin accounted for about 83.7% of the total isoflavones. The yields of SPI and isoflavones were about 48% and 30% in terms of their respective total contents in DSH. [Copyright &y& Elsevier]
- Published
- 2007
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