Pasta-Making Quality in Triticum durum. New Indices from the Ratio among Protein Components Separated by SDS-PAGE

Densitometric analysis of the gluten subunits as resolved by SDS-PAGE electrophoresis of 23 samples from seven varieties of durum wheat has provided further evidence for the positive effect on the quality of pasta made from durum wheat of low-molecular-weight glutenins (LMWG) and high-molecular-weight-glutenins (HMWG) and the negative influence of the intermediate-molecular-weight group (IMWG) (albumins, globulins, some glutenins, and omega gliadins). Differences in the expression of pasta quality were expected among the varieties investigated. However, high quality was invariably the result of a preferential accumulation of (LMWG) and (HMWG) in respect to IMWG. It appeared that such a biochemical feature could represent a general mechanism on which the pasta-making quality of durum wheat relies. The high correlation observed between the ratio (LMWG)/IMWG or (LMWG + HMWG)/IMWG and quality (r = 0.85^*** and 0.88^***, respectively) suggested that SDS-PAGE with densitometry of the gluten subunits could provide new quality indices useful in breeding durum wheats with improved pasta-making quality and for the grading of durum produce for industrial purposes.