Gluten viscoelasticity: Rapid method for classification of soft-like wheat genotypes

Authors: MONTAGNER, THIAGO - Oklahoma State University; DE MIRANDA, MARTHA - Embrapa; PRANDO, ANDRE - Embrapa; Tilley, Michael - Mike; PAYTON, MARK - Oklahoma State University; RAYAS-DUARTE, PATRICIA - Oklahoma State University

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2018
Publication Date: 3/12/2019
Citation: Montagner, T.S., De Miranda, M.Z., Prando, A.M., Tilley, M., Payton, M.E., Rayas-Duarte, P. 2019. Gluten viscoelasticity: Rapid method for classification of soft-like wheat genotypes. Cereal Chemistry. 96:167-181. https://doi.org/10.1002/cche.10128.
DOI: https://doi.org/10.1002/cche.10128

Interpretive Summary: The term flour quality has different meanings depending on the designation of use or type of product. The term 'technological quality of wheat generally indicates the performance of a wheat cultivar and it’s suitability in the preparation of an end-use product. Among the methods used to test wheat quality in breeding programs and baking industries are empirical and fundamental rheological tests (large and small deformations, respectively). However, the methods are often time consuming, some require a large amount of sample and specific training for execution. Gluten is the major and most crucial component of dough associated directly with bread quality. Gluten and dough are viscoelastic materials exhibiting properties of solid (cohesion and elasticity) and liquid (viscous or irrecoverable deformation). Bakers monitor dough viscoelasticity constantly using empirical methods while mills monitor their blends with laboratory methods including baking the final products. A rapid biaxial compression method was developed to test gluten elastic recovery using a Perten Gluten CORE Analyzer. The main advantages of this testing system are the instrument’s sensitivity and one minute test time. Brazilian wheat (soft-like genotypes) have a viscous and sticky textured gluten and requires a specific method to separate cultivars based on their viscoelastic properties. There is a need for an efficient method to evaluate rheological characteristics of gluten from Brazilian wheat genotypes, which may help to identify wheat for specific uses. This work presents progress toward the development of a rapid gluten test and provides further insight into the behavior of soft-type gluten under biaxial compression. The objectives of this study were: 1) to determine the best conditions for extraction of gluten from three commercial classes of Brazilian wheat genotypes.

Technical Abstract: Standard empirical methods to assess wheat quality are difficult to perform, interpret, time consuming and require a large amount of sample. A rapid biaxial compression instrument based on measuring height of gluten during compression and recovery is reported. The objective of this study was to determine in a set of soft like wheat genotypes from Brazil the best conditions to extract the gluten and analyze the efficiency of the method of separating categories based on gluten viscoelastic properties. The independent variables evaluated were: 1) technological quality categories, and gluten extraction method; 2) water added for dough formation; 3) mixing time; and 4) washing time. The experiment was designed in randomized blocks with factorial structure. The results were submitted to analysis of variance and means compared by protected LSD test (p<0.05). The best conditions for gluten extraction and analysis were obtained with 4.4 mL of water, mixing for 20 sec and washing for 3 min. Elastic recovery of gluten showed a strong correlation (r) with standard methods used to classify wheat (dough strength r=0.9885 and stability r=0.9632). The elastic recovery was able to separate the gluten samples in three categories efficiently and may be a useful tool in breeding programs and flour mills quality control.