Abstract:

Tianpei (sweet fermented oat) is a famous local snack in Lanzhou which is traditionally made by fermentation of
highland barley and oat for 2 or 3 days. In this paper, during fermentation, physicochemical changes were investigated, and
the production of ergosterol and proteolysis were monitored by high performance liquid chromatography (HPLC) and sodium
dodecyl sulfate polyacrylamide-gel electrophoresis (SDS-PAGE), respectively. Results showed that pH value decreased
rapidly and reached the lowest level of 3.90, and total acidity showed a gradual increase to the highest level of 0.74% as the
fermentation progressed. The content of ammonium nitrogen increased to the highest value of 0.06% during 24–36 h and
then dropped rapidly. Reducing sugar content increased significantly to the highest value of 41.17 g/100 g during the first
36 h and then decreased until the end of fermentation. Continually, the content of ergosterol augmented and reached its final
value of 213.64 μg/g. High-molecular-weight oat proteins were significantly hydrolyzed during fermentation, especially for
the protein with a molecular weight of 35.08 kD, which had a mean degradation rate of 55.57%.

Key words: sweet fermented oat, traditional culture starter, biochemical components, ergosterol, oat protein