|Budget Amount *help
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1991: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1990: ¥1,200,000 (Direct Cost: ¥1,200,000)
In all fungi investigated, Shiitake, Hiratake and Enokitake, the ergosterol was present in considerable amount, but no of little vitamin D_2 was present, Vitamin D_2 in all the sample of fungi was produced from ergosterol by sun or ultraviolet light irradiation. More vitamin D_2 in fungi, especially in Enokitake, was produced in ultraviolet light irradiation than in solar radiation. Scince significant amount of vitamin : D_2 in Enokitake was produced by ultraviolet light irradiation, the suitable conditions for irradiation, Umami taste, cooking and food processing of Enokitake were investigated to be available for an effective dietary source of vitamin D.
Contents of vitamin D_2 in Enokitake irradiated by ultraviolet light for 2 hours or 20 minutes were about 2000 IU or 1000 Id per gram in dry matter, , respectively. In view of the nutrition, irradiation by ultraviolet light for 20-30 minutes makes Enokitake into an effective source of vitamin D supply. . Few amount of vitamin D_2 produced in Enokitake was destroyed by drying and during storage for several monthe in cold chamber, but also Umami taste in irradiated dried Enokitake was increased significantly. Free amino acids and 5'nucleotide were present for Umami substances in dried Enokitake. ., That is, contents of glutamic acid, IMP and GMP were 820, 540 and 260 mg%, respectively. Scince synergistic effect in taste of the 5'-nucleotide in combination with glutamic acid was well-known, these results suggested that the presence of 5'-nucleotide and glutamic acid in dried Enokitake enhanced Umami taste.
Sensory test panel judged that addition of dried Enokitake to several cooking gave an increase in Umami taste or preference.