Studies of the methodology for fractionation and reconstitution of wheat flours

Abstract

A systematic study of the different steps in the separation, fractionation and reconstitution of wheat flours was undertaken to determine where detrimental changes to functional properties might arise. The effects of different variables are summarised. Some of the more important precautions that need to be observed are the extraction of lipid with an appropriate solvent as a first step, the washing out of gluten at an optimum temperature (15°C), minimisation of contact time for gluten protein fractions with acid solution, neutralisation of extracting solutions to the correct pH and grinding of freeze-dried fractions to a suitable particle size. A scheme is outlined for separating, fractionating and reconstituting flour components with complete recovery of original flour functional properties as determined by dough mixing and baked loaf parameters. Numerical results are given for two flours as a guide for workers wishing to adopt the procedure. Separation of the gluten protein of each flour into two approximately equal fractions, followed by interchange of fractions between the reconstituted flours, confirmed that baking quality differences are located mainly in the more insoluble (sediment) fraction.