New procedure for evaluating pasta-making aptitude of durum wheat semolina

Semolina with high protein content and strong gluten is recognized as the best raw-material for pasta-products with a good cooking quality, while little consideration has been given to semolina dough elasticity. None of the present techniques developed for evaluating dough elasticity seems to give satisfying information regarding pasta cooking quality. In this research, a new technique was developed by adapting the Glutograph (Brabender GmbH&Co., Germany) to measure the changes in elasticity induced by heating on a sheeted dough. The information obtained by this procedure was related to pasta cooking quality. Starting from semolina of six durum wheat varieties with differences in protein quantity and quality, dough samples were prepared in a Farinograph at a hydration level of 35%. Each of them was sheeted by a home-made pasta machine, obtaining disks of 5 cm diameter and 2.1 mm thickness. The pieces were stored at 30 °C for 40 min before analysis. Stretching (10 s) and relaxation (30 s) cycles were applied repeatedly during the test time, while dough temperature was increased from 30 to 90 °C at 1.2 °C/min. For each peak recorded, stretching and recovery values were calculated and plotted against sample temperature. Both stretching and recovery curves were integrated and the loss of elasticity was calculated. A number of critical variables were identified that, when controlled, provide consistent results. Results showed as high elasticity loss during heating is related to low firmness of the corresponding cooked pasta. Following testing with larger sample numbers, this technique has the potential to be a valid screening tool for durum wheat quality.