Towards the understanding of bread-making quality in organically grown wheat: Dough mixing behaviour, protein polymerisation and structural properties

Achieving high quality of organic bread is a major objective of organic wheat production. The aim of the present study was to understand the mechanisms related to bread-making quality in organically grown wheat genotypes from a diverse background. Fifty one organically grown winter and spring wheat genotypes were evaluated for percentage of unextractable polymeric proteins in total polymeric proteins (%UPP) in flour and dough, mixing behaviour and structural properties. The results showed a large variation in genotypes for %UPP in flour, changes in %UPP at mixing, mixing parameters and structural properties. Genotypes with high %UPP in flour and low change in %UPP at optimum mixing were; Agron, Hjelmqvist 6357 bla and Effrada. The light microscopy (LM) and confocal laser scanning microscopy (CLSM) results confirmed that genotypes with high %UPP in flour and a low change at optimal mixing resulted in a more extended protein network (continuous and interconnected) at mixing as compared to the other genotypes. Genotypes with good mixing properties as to the mixograph analyses were; Diamant ax, Lantvete Gotland 4496 spelt, Erbe brun and Jacoby 59. The present study shows the presence of opportunities to select genotypes suitable for cultivation and breeding of bread wheat for organic production. (C) 2012 Elsevier Ltd. All rights reserved.