Nutritional properties of Proso millet grown as a second crop in Minnesota

Millet is a drought-tolerant, nutritious gluten free grain high in resistant starch, thus well-suited for diabetics and people with celiac disease. As part of an ongoing evaluation of Proso millet as a double crop in Minnesota, our aim was to characterize six varieties (Dawn, Earlybird, Horizon, Snowbird, Sunrise, Sunup) of decorticated Proso millet grown in two locations in 2015 and compare them to a commercial Proso millet. Proximate analysis was conducted using standard methods, and pasting profiles measured with a micro viscoamylograph. Total and digestible starch was determined enzymatically. Color was measured on a chromameter, in addition to carotenoid quantification via HPLC. Growing location influenced moisture and lipid contents more than variety did, and both parameters were positively correlated. Dietary fiber contents tended to be influenced by variety but not growing location. Sample color most notably differed in lightness and yellowness, due to differences in carotenoid (lutein and zeaxanthin) content. Proso millet grown in Minnesota had lower pasting temperature, similar peak viscosity, higher breakdown and lower setback values than the commercial millet. Earlybird had lower pasting temperature, lower final viscosity and setback than all other millets, regardless of growing location. This variety had similar starch, protein and fat contents than other samples; however, it contained more soluble dietary fiber. In vitro starch digestibility of cooked samples was affected by growing location and variety, with Horizon having the least rapidly digestible starch and Dawn and Snowbird having the most slowly digestible starch. Our characterization of Proso millets will lead to the selection of specific varieties for breeding purposes that are best suited for the production of specific cereal-based goods such as wafers, cookies or bread.