The effect of kernel weight on the assessment of baking performance of wheats by RP-HPLC of glutenin subunits from single grains

Abstract

The baking performance of flour produced from grain fractions of the cultivar Otane increased with the average kernel weight of the fraction. The change in baking performance with kernel weight for flours produced from grain fractions was predicted using RP-HPLC. Studies using single grains showed that, for Otane, the proportions of all the wheat storage proteins increased as a function of kernel weight, and that there was a high degree of grain-to-grain and sample-to-sample variability in both the total protein and HMW glutenin content. The accuracy of baking performance predictions for single grains using RP-HPLC was greatly improved when multiple, rather than single, grain analyses were performed. No relationship was found between the mean kernel weight of individual samples and their baking performance. If this grain-size effect, and the high level of variability in protein content observed, can be demonstrated for other cultivars, then rejection of a cultivar from a breeding programme on the basis of a single kernel test would be ill-advised, regardless of the method used to measure protein content.