PROTEIN QUANTITY AND QUALITY AS FACTORS IN THE EVALUATION OF BREAD WHEATS

Abstract

In evaluating new wheat varieties for breadmaking quality, it is necessary to separate the effects of protein quality and protein content. By the remix bread baking test, there is a particular protein quality that gives the optimum baking performance. Poor baking results are obtained for wheats that are weaker or stronger as judged by the farinograph test. High-quality varieties such as Manitou give poor baking results by standard baking tests if the protein content is too low. For bread wheats of different protein quality, the loaf volume is positively correlated with protein content. Wheats that have too little or too much of the peculiar protein quality necessary for optimum bread quality as assessed by the remix baking test can be improved by physical modification of the dough by means of variable mixing. This procedure can be used in some cases to place wheats on a constant quality base, whereby different wheat varieties can give similar bread quality for the same protein content. For a single variety (Manitou) grown in the same location during two years, most of the standard breadmaking quality parameters are significantly correlated with protein content.