New food innovation is largely based on consumer demand, and currently many consumers demand healthy foods with clean label ingredient statements and plant-based origins. Sprouted grain products meet these qualifications and thus are growing in popularity. Sweetened products have been made from oats by adding exogenous amylase enzymes to hydrolyze starch into sugars. The purpose of this study was to create a clean label oat sweetener using endogenous enzymes. First, amylase activity under various sprouting conditions was determined for 4 hulless and 10 in-hull oat varieties. Paul (hulless variety) and Horsepower (in-hull variety) had the highest amylase activity after sprouting 120 h at 16°C. The amylase activity in these two varieties was then further optimized by determining the highest amylase activity occurred by sprouting for 120 hours at 24°C. Second, amylase activity was determined for these two varieties after oven-drying and freeze-drying of sprouted oats, followed by a 4-week ambient storage period. Paul decreased in alpha-amylase activity for both oven-dried and freeze-dried samples, whereas Horsepower remained constant in its amylase activity for oven-dried and freeze-dried samples. Stored samples were also analyzed for susceptibility to lipid oxidation using SPME-GC-MS. All hexanal levels rose during the 4-week storage study except for the oven-dried Paul samples which began high and decreased over time. Third, a slurry of sprouted Horsepower oats, oat flour, and water was incubated at 45, 55, and 65°C to determine the optimal temperature needed to create a sweetened paste for use in oat-based food products. Incubation at 55°C had the highest initial rate of sugar production as measured by normal phase HPLC. Amount of sugar produced increased over time and plateaued at 6 h.



College and Department

Life Sciences; Nutrition, Dietetics, and Food Science



Date Submitted


Document Type





oats, amylase activity, endogenous enzymes



Included in

Life Sciences Commons