EFFECT OF PUROINDOLINES ON THE BREADMAKING PROPERTIES OF WHEAT-FLOUR

The role of lipid-binding proteins from wheat seed (puroindolines) on the breadmaking properties of wheat flour was investigated by determin ing the relationship between breadmaking quality and puroindoline cont ent in samples of 32 wheat cultivars. An inverse relationship was main ly explained by the link between hardness and puroindoline contents. T his link is in agreement with previous results which have shown a clos e structural identity between basic friabilins and puroindolines. Next , the effect of puroindolines in breadmaking was investigated by perfo rming reconstitution experiments with two puroindoline-free hard culti vars of opposite quality (Florence Aurore and Ecrin) as indicated in t he screened wheat sample. Addition of 0.1% puroindolines to these flou rs drastically modified both the rheological properties of doughs and the structure of the bread crumb. Puroindolines are essential to the f oaming properties of dough liquor, and a close relationship was found between the fine grain crumb provided by reconstituted flours with pur oindolines and the fine structure of corresponding dough liquor foams. The effect of puroindolines on bread volume was mainly related to the rheological properties of wheat doughs.