Structure of cooked spaghetti of durum and bread wheats

The structure of cooked spaghetti of durum and bread wheats was studied using low voltage scanning electron microscopy, and light microscopy applying different staining methods. Central, intermediate and external regions, and four zones along the external region of cooked spaghetti strands, were characterized in unprecedented detail. Changes in structure of starch granules from core to surface portrayed the successive stages in starch gelatinization, and possible starch retrogradation in the external region. Pronounced changes in shape of starch granules commenced in the intermediate region, while apparent internal changes dominated in the external region. Spaghetti of bread wheats differed from that of durum wheats by the larger size and higher extent of fusions and retrogradation of starch, and less amounts and continuity of intervening proteins. The significance of a high protein concentration for pasta production from bread wheats was emphasized. Furthermore, the relevance of a small size of the large starch granules was inferred.