The effects of processing and extraction conditions on content, profile, and stability of isoflavones in a soymilk system.

The effect of processing temperature and pH as well as enzyme-assisted extraction on the content and profile of isoflavones in a soymilk system was investigated. Isoflavone content in thermally treated soymilk at pH 7 and pH 9 was determined following a standard solvent extraction or an enzyme-assisted extraction protocol. Upon thermal processing, at both pH 7 and pH 9, significant interconversions were noted, indicated by the observed decrease in malonylglucosides with the concurrent increase in beta-glucosides.

Kinetic modeling of malonylgenistin and malonyldaidzin conversions under alkaline conditions and elevated temperatures.

The conversion and degradation of malonylglucosides were kinetically characterized under elevated pH/heat conditions. Malonylgenistin and malonyldaidzin were heated at 60, 80, and 100 degrees C and pH values of 8.5, 9, and 9.

Heat and pH effects on the conjugated forms of genistin and daidzin isoflavones.

Isoflavones occur primarily as glycosides (namely, malonyl-, acetyl-, and non-conjugated beta-glycosides) and a small percentage as the bioactive aglycon. The different chemical structures of isoflavones can dictate their stability during processing. Therefore, our objective was to determine the effects of pH and thermal treatments on conjugated isoflavones with regard to interconversions and loss.

FTIR determination of ligand-induced secondary and tertiary structural changes in bovine plasminogen.

Human plasminogen undergoes a large tertiary structural change in the presence of lysine derivatives (e.g. epsilon-amino caproic acid, EACA).