Evaluation of biochemical and technological quality attributes for 21 durum wheat cultivars grown in Egypt

Grain samples of 21 durum wheat cultivars from various world sources, grown under the same conditions in Egypt, were milled into both semolina and whole meal, and subjected to the biochemical and technological tests currently in use. Whole meal samples were analysed for their protein contents, both soluble and insoluble-residue fractions isolated with water, 0.5 mol NaCl, 70\% ethanol and 0.1 mol acetic acid were determined. Analysis of variance was carried out to compare the quality attributes of cultivars. Simple correlation coefficients among all quality parameters were calculated to determine the interrelationship of quality parameters. All quality attributes were typically variety-dependent and showed wide ranges of values. Pasta brownness can be predicted by wheat ash and protein contents (specially insoluble), and yellowness by carotene content. Brownness was usually associated with the good cooking quality of pasta. Total protein content and tests relevant to gluten quality (sodium dodecyl sulfate-sedimentation and mixograph characteristics) were strongly associated with each other, but where not efficient to predict pasta cooking quality. Good correlations were found between pasta cooking quality parameters (firmness and tolerance to overcooking) and insoluble-residue protein fractions, specially those isolated with both acetic acid and ethanol, suggesting the possibility of a whole meal index for predicting pasta cooking quality. Such an index is relatively simple, requires only small amounts of grains, and might be used for early generations of durum wheat breeding programs.