Optimization of Vitamin D₂ Production using Enoki Mushroom Powder and the Preparation of Doenjang using the Powder

다국어 초록 (Multilingual Abstract)

Optimization of vitamin D₂ production in enoki mushroom (Flammulina velutipes) using response surface methodology (RSM), and the effect of adding Enoki mushroom on the general quality characteristics of Doenjang during the fermentation process were studied. For the conversion of ergosterol in enoki mushroom powder to vitamin D₂ via ultraviolet-B (UV-B), the three independent variables of exposure time (40∼120 min), ambient temperature (10∼30℃) and irradiation intensity (0.9 ∼2.1 W/m²) were investigated. The ridge analysis predicted that a maximum yield of 393.73 μg/g was obtained when ambient temperature, exposure time, and irradiation intensity were 23.54℃, 82.33 min and 1.11 W/m2, respectively. During the fermentation process, in comparison with the control sample, bacterial and yeast counts, pH value, protease activity, amino-type nitrogen content, vitamin D₂ content and 5’-nucleotides contents increased in Doenjang after adding enoki mushroom. Beyond this, the addition of enoki mushroom reduced total acidity and had no effect on reducing sugar content, total amylase or α -amylase activity in Doenjang.