title: Isoflavone extraction from okara using water as extractant.
abstract: We here report on the use of water as a 'green' extraction solvent for the isolation of isoflavones from okara, a by-product of soymilk production. At a low liquid-to-solid ratio of 20 to 1 and 20 °C, 47% of the isoflavones that can be extracted with 70% aqueous ethanol were extracted. The malonyl-glucosides were fully recovered with a ratio of 20 to 1, while β-glucosides were recovered with an increased liquid-to-solid ratio of 40 to 1. The extraction of aglycones was better at higher ratios, but leveled off before reaching a 100% yield. Temperature hardly affected the total amount of isoflavones. At a 20 to 1 ratio, 20 °C, and pH 10, there was no significant difference (p>0.05) between isoflavone extraction in water and in 70% aqueous ethanol. The results suggest that water may be used as a green alternative for separation of isoflavones from okara.
authors.affiliation: Laboratory of Food Engineering, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Lena
authors.initials: L
authors.lastname: Jankowiak
authors.affiliation: Laboratory of Food Engineering, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kantzas
authors.affiliation: Laboratory of Food Engineering, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Remko
authors.initials: R
authors.lastname: Boom
authors.affiliation: Laboratory of Food Engineering, Wageningen University, P.O. Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: atzejan.vandergoot@wur.nl.
authors.forename: Atze Jan
authors.initials: AJ
authors.lastname: van der Goot
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D007529:Isoflavones / Q000032:analysis / Q000302:isolation & purification*; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification*; D010940:Plant Proteins / Q000032:analysis / Q000302:isolation & purification*; D011134:Polysaccharides / Q000032:analysis / Q000302:isolation & purification*; D045730:Soy Foods / Q000032:analysis; D013025:Glycine max / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D007529:Isoflavones; D010936:Plant Extracts; D010940:Plant Proteins; D011134:Polysaccharides; C412882:okara, Glycine max; D014867:Water
keywords: Aglycones; Glucosides; Okara; Protein–isoflavone interaction; Water extraction