Small‐scale methods to assess the gluten properties of durum wheat

Abstract

Background and objectivesDurum breeders are interested in being able to remove weak gluten genotypes from their crossing populations. Although numerous tests exist to measure gluten strength, methods that can be used in early generations, use minimal sample with little processing and have good discrimination are lacking. The purpose of this work was to evaluate several small‐scale methods to predict gluten strength in durum wheat with emphasis on the gluten aggregation behavior measured using a GlutoPeak device.FindingsUsing as little as 9 g of wholemeal (or semolina), a reproducible GlutoPeak aggregation curve is developed at the end of 5 min. Wholemeal gave higher precision than semolina and is more convenient to prepare when screening breeders’ material. The GlutoPeak Area and Peak Mixing Time (PMT) are good predictors of mixograph and gluten index (GI), which are traditional measures of gluten strength. Good correlations between these parameters were obtained using a diverse set of 145 durum genotypes. GlutoPeak Area gave the best prediction of GI from wholemeal samples allowing a breeder to remove weak‐moderate GI samples from a population using as little as 9 g of wholemeal. The GlutoPeak test showed higher correlations with mixograph and GI than the small‐scale biochemical methods, was easier to perform and uses no chemicals. However, GlutoPeak is not suitable when only mg quantities of sample are available.ConclusionsThe utility of the GlutoPeak device has been further validated in this work for screening durum wheat lines for gluten strength. Wholemeal is a suitable sample (9 g minimum) and provides good precision and reproducibility with a short analysis time of 5 min and requires minimal operator skill. It is suited to screening breeders’ populations for gluten strength and is preferred over SIG, HPLC determination of UPP and IP% determination using a turbidity assay.Significance and noveltyThe GlutoPeak can be used to effectively screen out low‐intermediate gluten strength in a durum wheat breeders’ population using 9 g of wholemeal with a 5 min run time.