The structural arrangements of proteins and polysaccharides in wheat flour are one of the most important factors that influence the breadmaking and pastamaking technological properties. These structures determine the molecular interactions within the flour and those deriving from the technological treatment. These interacting structures were studied at the molecular level using chemical probes.

Spectrofluorimetric determinations of the bound ANS (8-aniline-l-naphtalene sulfonate) to the gluten proteins allow to calculate surface hydrophobicity, distribution and type of hydrophobic areas. These parameters were determined on native and denatured gluten and were interpreted in function of the breadmaking performance.

A stepwise reduction with dithiotreitol (DTT) of wheat proteins, in conjunction with electrophoretic  techniques, was used as a chemical probe of their organisation. This evidenced in gluten proteins the accessibility of disulphide bonds in different breadmaking steps.

Protein primary free amino groups can be  labelled with molecules containing a carboxyl functional group by the mixed anhydride technique. We have devised a new approach using the hemisuccinate of 2-(2,4-dichlorophenyl)-3-(lH-1,2,4-triazollyl) propanol (FF18) as the labelling compound. The availability of anti BSA-FF18 serum allowed us to immunodetect the labelled proteins. The approach applied to the gluten proteins gave important information on their accessibility.

Also enzymes can be used as probes of protein and starch status. Hindered access of amyloglucosidase to polysaccharides in presence of gluten or isolated gliadin and glutenin  detects  the  existing  interactions among these flour macromolecules.

In this paper, results obtained using the probe approach will be discussed and reviewed.