Submitted to: Journal of Cereal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/25/2006
Publication Date: 6/1/2006
Citation: Schober, T.J., Bean, S., Kuhn, M. 2006. Gluten proteins from spelt (Triticum aestivum ssp. spelta) cultivars: A rheological and size-exclusion high-performance liquid chromatography study. J. Cereal Sci. 44(2): 161-173. Interpretive Summary: Spelt is an ancient relative of modern bread wheat. Although once the predominant grain in many parts of Europe, it has largely been displaced by modern wheat in the 20th century. Nevertheless, in the past few decades it has undergone a renaissance as a niche product in Europe and the US, partly due to consumers’ perception of it being healthier, more natural or less ‘over-bred’ than modern wheat. In comparison to modern wheat, however, little is known about quality differences between large numbers of old and newly bred spelt cultivars. The present study investigated the biochemical basis of spelt quality with state-of-the-art methods. Twenty-five European cultivars were divided into quality groups. The biochemical basis for the poorer quality of some cultivars as well as some typical spelt quality traits could be identified. These results can help US breeders in the development of new cultivars with desired traits.
Technical Abstract: The aim of this study was to understand protein chemistry behind gluten quality of spelt (Triticum aestivum ssp. spelta), to classify European spelt cultivars based on gluten quality, and to compare their protein composition to modern wheat. Gluten quality of two sets of 25 spelt cultivars was studied by fundamental rheology (dynamic oscillatory and creep tests), SDS sedimentation test, moisture content of the wet gluten and wet gluten content. These data were compared to the results of size-exclusion HPLC analyses of the spelt proteins. Significant correlations indicated that the amount of insoluble polymeric proteins (IPP) contributed resistance to deformation in creep tests, elasticity in oscillatory and creep tests, and swelling capacity of the gluten. Gliadins had the opposite effects, whereas the contribution of soluble polymeric proteins (SPP) depended on the type of test. In creep tests (strain 0.3-1.5) SPP acted similar to gliadins, in oscillation (strain 0.001) they tended to increase elasticity. Spelt, in comparison to hard red winter wheats, was characterized by lower IPP, but higher SPP and gliadins, resulting in softer and less elastic glutens. A wide variation in gluten quality was found within spelt and three groups could be identified by cluster analysis (closer to modern wheat, typical spelt and poor quality).