INTERACTION ENTRE L’AMIDON ET UNE FRACTION PROTEIQUE EXTRAITE DES SEMOULES DE T. DURUM

Abstract

In order to establish if there was a relationship between specific biochemical parameters and semolina quality, an analysis of interaction between starch and a specific protein fraction was performed on nine semolina samples of five cultivars of durum wheat grown in two locations in Italy. The starch was extracted with 2% NaCl and purified with water and 85% methanol in each sample. The protein fraction used was that soluble in acetic acid 0.1 N and then precipitated at pH 6.5, isolated from each semolina. The swollen purified starch and the protein fraction redissolved in acetic acid 0.1 N from the same semolina sample were allowed to react under controlled conditions. The protein and amylose reacted linearly. The slope of regression lines was different for each sample; these differences reflected different affinity of protein and amylose. The protein fraction (gliadines solubles in acetic acid) and the starch have also been characterized by electrophoretic pattern and by viscosity measurements, respectively.Key words: Starch, acid soluble protein, Triticum durum