ENHANCING DURUM WHEAT RESISTANT STARCH, DIETARY FIBER, AND PASTA QUALITY

Diets high in fiber help protect against obesity related health conditions. Most consumers prefer non-whole grain wheat products, therefore testing of health enhanced alternatives with enhanced product quality is worthwhile. One way to achieve a healthier cereal product is to begin with grain with increased resistant starch and dietary fiber. This can be achieved by reducing or knocking out the function of starch synthase IIa (SSIIa). Increased amylose in current durum lines leads to improved pasta quality, though seed size and milling yields are greatly reduced.The overall goal of this project is to improve pasta quality while maintaining seed size and yield. Here we will test the impact of individual ssIIa mutations and allelic combinations upon durum agronomic yield, amylose, dietary fiber, resistant starch, pasta quality, and consumer preference. We will also identify gene expression and specific SSIIa activity levels necessary to maintain seed size while increasing dietary fiber and pasta firmness. This project will result in genetic material available for use in durum breeding programs. High resistant starch durum would greatly lower food processing costs and increase the availability of healthy, consumer accepted wheat-based products.Our specific objectives are:1. Test novel SSIIa allele combinations to determine their relative impact upon plant yield-related characters.2. Carry out molecular experiments to measure in vitro activity of variant SSIIa enzymes, transcript stability, and protein binding properties.3. Perform product quality testing of high and intermediate amylose pasta and carry out taste tests to examine how amylose content affects consumer preferences.