Improving Shelf Life and Flavor of Whole Grain Flour

The USDA recommends that “at least one serving of grains per day must be whole grain-rich” due to evidence that a diet containing whole grains provides a multitude of benefits, including lower risk of obesity, cardiovascular disease, and type-2 diabetes. Despite these health benefits, consumption of whole grain products is negatively affected by the bitter and rancid flavors and odors that accumulate from the degradation of lipids during storage. Using TILLING (Targeting Induced Local Lesions in Genomes), a non-transgenic method, we have developed novel wheat lines with improved stability of whole grain flour. We targeted enzymes catalyzing hydrolytic and oxidative lipid degradation including lipases and lipoxygenases. In hexaploid wheat, we identified and combined knock-out alleles in both a highly expressed mature grain lipoxygenase (Lpx1) and lipase (Lip1). Our novel alleles in Lip1 produced lines with reduced lipase enzyme activity that improved hydrolytic stability of lipids. Novel alleles in Lpx1 greatly reduced the production of rancid and bitter compounds in aged whole grain flour. Wheat lines with these novel traits are being tested further for sensory characteristics and shelf life stability. These new traits, singly and in combination could help improve the shelf life and flavor of whole grain products.