ABSTRACT
This study was conducted to determine the most efficient method to produce vitamin D in mushrooms using UV radiation. For this purpose, mushrooms were irradiated with UV-B and UV-C lamps from their caps, stems, both caps and stems (oblique), and sliced surface at doses of 12.5 kJ m-2 and 3.6 kJ m-2, respectively. Then, they were treated by UV-B at 27 °C, 35 °C, and 43 °C. In the next steps, samples were placed in 30 cm and 50 cm distances from the UV source. Afterward, they were irradiated from 15 to 120 min at an intensity of 3.5 W m-2. In the stability tests, samples were stored at 25 °C, frozen, refrigerated and were cooked and their vitamin D2 content was re-analyzed using HPLC. All experiments were repeated three times. In the sliced group treated with UV-B, vitamin D2 content 14.43 µg gr-1 was significantly higher than other groups. The internal temperature of 27 °C was found as optimum temperature with the production of 3.81 µg gr-1 vitamin D. It was revealed that increasing the distance from the UV source had a significant effect on vitamin D production. After 90 min of exposure, the highest amount of vitamin D2 was produced. Data showed that the vitamin D2 content remained almost stable after one day at 25 °C and during the cooking but it decreased about 50% after 7 days of cold storage. The optimal method observed in this study incorporates the use of UV-B lamps, incensement of radiation area in mushrooms and distance reduction from the UV source within 30 cm the internal temperature of 27 °C should be considered as well in the experiment.
