title: Recovery of isoflavone aglycones from soy whey wastewater using foam fractionation and acidic hydrolysis.
abstract: The purpose of this work was to recover isoflavone aglycones from industrial soy whey wastewater, where the isoflavone aglycones mainly existed in the form of β-glycosides. First, foam fractionation was used for effectively concentrating the total soy isoflavones, including isoflavone aglycones and β-glycosides, from the wastewater. Fourier transform infrared spectroscopy indicated the existence of complexes of soy isoflavones and soy proteins. When soy proteins were used as the collectors, a high enrichment ratio of 3.68 was obtained under the optimal operating conditions of temperature of 50 °C, pH of 5.0, volumetric air flow rate of 100 mL/min, and loading liquid height of 400 mm. Subsequently, acidic hydrolysis was used for hydrolyzing β-glycosides in the foamate into aglycones. Using response surface methodology, a hydrolytic percentage could reach 96% under the optimum hydrolysis conditions of hydrolytic temperature of 80 °C, hydrochloric acid concentration of 1.37 mol/L, and hydrolytic time of 90 min.
authors.affiliation: School of Chemical Engineering and Technology, Hebei University of Technology, Hongqiao District, Tianjin 300130, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Hui Xin
authors.initials: HX
authors.lastname: Zhang
authors.forename: Zhao Liang
authors.initials: ZL
authors.lastname: Wu
authors.forename: Yan Ji
authors.initials: YJ
authors.lastname: Wang
authors.forename: Lian Jie
authors.initials: LJ
authors.lastname: Wang
mesh_terms: D000143:Acids / Q000737:chemistry; D005591:Chemical Fractionation; D006868:Hydrolysis; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D013025:Glycine max / Q000737:chemistry*; D014866:Waste Products / Q000032:analysis*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D000143:Acids; D007529:Isoflavones; D010936:Plant Extracts; D014866:Waste Products; D062065:Wastewater