| Abstract
| - Isoflavones occur primarily as glycosides (namely, malonyl-, acetyl-, and non-conjugated β-glycosides)and a small percentage as the bioactive aglycon. The different chemical structures of isoflavonescan dictate their stability during processing. Therefore, our objective was to determine the effects ofpH and thermal treatments on conjugated isoflavones with regard to interconversions and loss.Conjugated daidzin and genistin were heated at 25, 80, and 100 °C under neutral, acidic, and basicconditions. Changes in isoflavone derivatives were monitored using high-performance liquid chromatography. Along with interconversions, considerable loss in total known isoflavone derivatives wasnoted for each isoflavone, especially under elevated pH and temperature. The malonylglycosidesshowed more stability than acetylglycosides, especially under acidic conditions. Overall, loss inisoflavone derivatives was significantly higher for daidzin than for genistin glycoside forms. Our resultshighlighted the significance of chemical structure with regard to stability, which is a key factor indetermining soy processing conditions. Keywords: Isoflavones; β-glycosides; malonylglycosides; acetylglycosides; stability; pH; processingconditions
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