Gluten as a Standard of Wheat Flour Quality
Duška Ćurić*, Damir Karlović, Dubravka Tušak, Biserka Petrović and Jelena Đugum
Department of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, HR-10000 Zagreb, Croatia
Article history:
Received August 3, 2010
Accepted February 3, 2011
Key words:
wheat, flour, gluten index, physical dough properties
Summary:
The quantity and quality of gluten are considered the most important quality parameters of wheat flour. Gluten Index Method (GIM) is a rather new method for determining gluten quantity and quality in wheat semolina and flour. This study reports on values for flours obtained from the most important Croatian wheat cultivars. The gluten index value in the tested flour samples varied from 55.92 (Patria cultivar) to 99.60 % (Marija cultivar).This high variety was not only due to cultivar differences but also to different climate conditions (especially cultivars Žitarka and Sana). The determination of gluten quantity and quality by Gluten Index Method is compared with the determination by other methods. A significant positive linear correlation was observed between the values of gluten index and extensographic values of flour quality, i.e. between the gluten index and maximal resistance of dough to extensibility (r = 0.860), dough energy (r = 0.799) and dough resistance at 50 mm (r = 0.788). That indicates that the gluten index actually defines technological flour quality. The optimal gluten index values for bread production using Croatian wheat cultivars were between 75 and 90 %.
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