Impact of Cultivar and Environment on Size Characteristics of Wheat Proteins Using Asymmetrical Flow Field‐Flow Fractionation and Multi‐Angle Laser Light Scattering

Abstract

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.

Wheat response to a wide range of temperatures, as determined from the Hot Serial Cereal (HSC) Experiment

“…Starch granules were extracted following Bancel et al (2010) and the volume percentages of A-(diameter > 10 µm), B-(2 µm < diameter < 10 µm), and C-(diameter < 2 µm) granules were determined by using a laser beam scattering apparatus (Debiton et al, 2011). The size distribution and radii of glutenin polymers was analyzed by asymmetric flow field-flow fractionation (AF4) coupled with a multi angle laser light scattering (MALLS) detector (Lemelin et al, 2005). Flour starch content was determined as described by Hendriks et al (2003).…”

Storage Proteins Accumulation and Aggregation in Developing Wheat Grains

“…Flow field-flow fractionation (FFFF) [43][44][45][46], which is a new separation technique without any stationary phase, and which is therefore not hampered by a steric exclusion limit [47][48][49], has been used successfully to separate a number HMW fractions [50][51][52]. Furthermore, the MALLS technique which is one of the most effective means of determining molecular weight, size and conformation of glutenin polymers without reference to standards [48,[53][54][55][56] has been applied in combination with the A-FFFF method to accurately measure size and conformation of wheat glutenins [57] ( Figure 5).…”

“…Asymmetrical flow field-flow fractionation (A4F) profiles of total solubilized storage proteins of a common French wheat cultivar (Soissons). UV (blue line), light scattering at 90° (red line) and molecular weight in relation to elution time (dark line) (from Lemelin et al[57]). …”

Polymeric Proteins, Rheological Properties and BREAD Making Quality of Durum Wheat Flours and Semolina

“…UPP showed a wide variation among the flours / semolina with DFCF1 (43,3%) having the lowest and DF (47,90%) the highest proportion. The differences in extractability of the polymeric proteins could be attributed to differences in degree of polymerization (Singh et al, 2011).The difference of amount of UPP between samples can be explained from different quaternary structure [7]. 3.3 Rheological properties of flours/semolina Table III give rheological data for flours and semolina.…”