New Technologies for Whole Wheat Processing: Addressing Milling and Storage Issues

Whole wheat flour production and demand has increased dramatically during the last decade due to evidence supporting the benefits of whole grains in the diet. Hence, the food industry has provided a wide variety of new whole grain products. There are unique challenges that accompany whole wheat flour production, especially related to milling and storage. The present thesis provides new strategies on the adaptation of new technologies to overcome whole wheat processing issues. These issues are first discussed in a literature review and then followed by three research studies. In the first study, retail whole wheat flours were evaluated for particle size distribution to determine variations in currently available products. Significant differences were found for particle size distribution among and within brands. Compositional data elucidated differences in the degree to which the bran fraction of the kernel was milled. In the second study we aimed to produce whole wheat flour in the laboratory that could be used for end-use quality testing. We varied the moisture content during milling to produce flours with different particle size distributions and evaluated the functional properties of the flours. Mean particle size of the coarse fraction (\u3e230 μm) decreased as moisture content decreased. Wheat milled at lower moisture contents (i.e., 6.89-7.98%) provided flours with better functionality and mixing properties. In the third study, salts were added to wheat during tempering to reduce lipolytic activity in an effort to extend shelf life of whole wheat flour. This strategy was effective at inhibiting lipase, and provided flour with better baking properties than the control after 6 months of storage. The outcomes of these studies serve as new strategies for the production and evaluation of whole wheat flour. Adviser: Devin J. Ros