DisplayTitle

Impact of Cultivar and Environment on Size Characteristics of Wheat Proteins Using Asymmetrical Flow Field-Flow Fractionation and Multi-Angle Laser Light Scattering^1,2

¹Research supported by a grant from Conseil Régional Midi-Pyrénées, Contract RECH 99008103. ²This work is based on a poster presented at the AACC Annual Meeting, 2002, Montréal, Canada. ³ESAP, 75 voie du Toec, 31076 Toulouse cedex 03, France. ⁴Corresponding author. E-mail: thierry.aussenac@isab.fr ⁵ISAB, rue Pierre Waguet, 60026 Beauvais cedex, France. ⁶Grands Moulins de Paris, 44 route principale du Port, 92238 Gennevillier cedex, France. ⁷Saaten Union, 163 avenue de Flandre, 60190 Estrees, France.

The use of multi-angle laser light scattering (MALLS) in conjunction with asymmetrical flow field-flow fractionation (A-FFFF) was investigated for the determination of the molecular weight distribution (MWD) of wheat proteins. The wheat flour proteins were dissolved by sonication in 0.1M sodium phosphate (pH 6.9) containing 2% SDS. The results presented make it evident that efficient separation and size characterization of monomeric (M < 10⁵ g/mol) and polymeric protein (10⁵ ≤ M < 10⁸ g/mol) wheat proteins can be achieved with A-FFFF/MALLS/UV in a single run. Therefore, this method appears to be able to detect significant modifications of MWD of wheat protein, whatever the factor inducing these alterations (i.e., genetic or environmental) and whatever the nature of these alterations (i.e., monomeric-to-polymeric ratio or MWD of polymeric protein). In the present study, we have indeed demonstrated that the MWD of wheat proteins can be altered from one cultivar to another in three main ways: by changing the relative amounts of monomeric and polymeric proteins, by changing the MWD of polymeric protein, and then by changing both the monomeric-to-polymeric ratio and the MWD of polymeric protein.