Submitted to: Cereal Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/7/2001
Publication Date: 6/15/2001
Citation: Grant, L.A., Vignaux, N., Doehlert, D.C., McMullen, M.S., Elias, E.M., Kianian, S. 2001. Starch characteristics of waxy and nonwaxy tetraploid (triticum turgidum L. var. durum) wheats. Cereal Chemistry. 78:590-595. Interpretive Summary: Durum wheat has always been the grain of choice for producing quality pasta products. With the recent development of waxy durum wheat, it has been necessary to examine its starch properties to determine their usefulness in terms of functionality. The fact that waxy durum wheat starch is essentially 100% amylopectin may dramatically influence the behavior of the starch under normal processing conditions. This study examined functional properties such as how much water the starch granules can hold (swelling capacity), how thick a paste can be made when heated (pasting viscosity), and the starches tendency to bread down when held for a period of time at serving temperatures (stability) or at room temperature (retrogradation). Knowledge of these facts will help the future creation of new pasta products and\or uses of waxy durum wheat.
Technical Abstract: The manufacture of pasta products is paramount for durum wheat. The recent development of waxy durum wheat containing starch with essentially 100% amylopectin may provide exciting new food processing applications and present opportunities for value added crop production. This investigation was conducted to determine differences in the functional properties of waxy durum starch. Starch was isolated from two waxy endosperm lines (Wx-0 and Wx-1) and four nonwaxy cultivars of durum wheat. Effects on starch swelling, solubility, pasting, gelatinization and retrogradation were examined. Full waxy starch had four times more swelling power than nonwaxy durum starch, but was also more soluble at the four temperatures utilized. Starch pasting occurred earlier and peak viscosity was greater than for the nonwaxy durum starch, but the slurry was less stable with continued stirring and heating. Greater energy was required to melt gelatinized starch gels, but refrigerated storage retrogradation and freeze-thaw retrogradation as determined by differential scanning calorimetry (DSC) indicated less stability than starches from nonwaxy durum wheat. The results of this investigation showed significant differences in the starch properties of the waxy durum lines compared to nonwaxy durum wheats.