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Influence of Low Molecular Weight Glutenins on Viscoelastic Properties of Intact Wheat Kernels and Their Relation to Functional Properties of Wheat Dough

¹Centro de Investigación y de Estudios Avanzados. Ciencia de Materiales. Área de materiales bio-orgánicos (CINVESTAV-Unidad Querétaro), Libramiento Norponiente 2000, Fracc. Real de Juriquilla, Querétaro, C.P. 76230 Qro., México. ²University Applied Science Furtwangen, Jacob-Kienzle Str. 17, 78054 Villingen-Schwenningen, Germany. ³Corresponding author. E-mail: figueroa@ciateq.net.mx ⁴CIMMYT, km 45 Carretera México Veracruz. El Batán, Texcoco, México C.P. 56130.

The mechanical and viscoelastic properties of intact wheat kernels of 36 wheat cultivars differing in low molecular weight glutenin subunit (LMW-GS) composition (loci Glu-A3, Glu-B3, and Glu-D3) were evaluated using load-compression tests. Comparison among genotypic groups representing Glu-3 allelic variants showed that groups representing the alleles Glu-A3 b, c, and d; Glu-B3 d, g, and h; and Glu-D3 a, b, and d, had harder kernel texture, higher kernel elastic work and larger gluten strength-related parameters than those possessing alleles Glu-A3 e; Glu-B3 f, i and j (translocation 1B/1R); and Glu-D3 d. Modulus of elasticity (stress to strain ratio) showed low values (111.9–168.8 MPa) for allelic groups possessing poor elastic properties (Glu-A3 e; Glu-B3 f, i, and j; and Glu-D3 d), and high values (179.8–222.6 MPa) for allelic groups possessing high kernel elastic properties (Glu-A3 b c, and d; Glu-B3 d, g, and h; and Glu-D3 a, b and c). The highest values for gluten strength-related parameters (SDS-sedimentation, dough mixing time, and dough strength [W]) corresponded to allelic groups Glu-A3 d; Glu-B3 d and g; and Glu-D3 d, while the lowest corresponded to Glu-A3 e and Glu-B3 j. No significant differences were observed among groups with regard to gluten extensibility parameters; however, the highest P/L value (least extensibility) corresponded to Glu-B3 j, which indicates presence of 1B/1R translocation. Except for the Glu-B3 j (translocation 1B/1R) allele, which presented more variation within samples, a general relationship between kernel viscoelastic properties and dough viscoelastic properties was observed; samples showing higher elastic work to plastic work ratio (E/P) tended to possess better gluten strength than cultivars with low E/P ratio.