Suitability of reverse micelles of anionic surfactant sodium bis(2-ethyl hexyl) sulfosuccinate (AOT) and sodium dodecyl sulfate (SDS), cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) and nonionic surfactant polyoxyethylene p-t-octylphenol (TritonX-100) in organic solvent isooctane for extraction of soy isoflavone-enriching proteins was investigated. The results showed that the order of combined isoflavone contents was SDS>CTAB>Triton X-100>AOT, while the order of protein recovery was SDS>AOT>TritonX-100>CTAB. As compared with ACN-HCl extraction, the total amount of isoflavones was lower than reverse micellar extraction. Ion strength was one of the important conditions to control extraction of isoflavone-enriching proteins with AOT reversed micelles. For the six salt systems, KNO3, KCl, MgCl2, CaCl2, NaCl, and Na2SO4, extracted fraction of isoflavone-enriching proteins was measured. Salt solutions greatly influenced the extraction efficiency of isoflavones in an order of KNO3>MgCl2>CaCl2>KCl>NaCl>Na2SO4, while protein in an order of MgCl2>CaCl2>NaCl>KNO3>Na2SO4>KCl.
