RELATIONSHIPS BETWEEN MIXOGRAPH PARAMETERS AND INDEXES OF WHEAT-GRAINQUALITY

A 10-gram Mixograph was used to analyse 39 bread wheat cultivars havin g various agricultural characteristics and origins. Eleven parameters obtained during the first 8 minutes of the mixing procedure were selec ted using a repeatability analysis in order to investigate variations between genotypes. Several flour protein fractions characterised by th eir extractability properties and size distributions were quantified. In addition grain hardness, water-extractable arabinoxylan contents an d relative arabinoxylan viscosity were also determined and correlated with dough formation during mixing. Dough consistency, as measured by the height of the Mixogram, was correlated with grain hardness, as exp ressed by the starch damage content and the proportion (%) of flour pa rticles larger than 37.8 mu m. No significant relation was found with the water-extractable arabinoxylan content or the relative arabinoxyla n viscosity. The width and height of the Mixogram was related to the p roportion of unaggregated proteins before the mixing peak and to polym eric proteins after the dough consistency reached a maximum. The Mixog raph proved to be a powerful tool to investigate indices of bread maki ng quality. (C) 1998 Academic Press Limited.