水溶性和醇溶性红曲色素的光稳定性

Photostability of Water-Soluble and Alcohol-Soluble Monascus Pigments

利用照度计量化红曲色素所接受的光,研究不同光照强度、波长和照射时间对红曲色素保存率的影响。结果表明:阳光(2 800~31 000 lx)对红曲色素的光降解最为显著;室内自然光(54~2 050 lx)对红曲色素的光稳定性影响较小,避光条件(0 lx)对红曲色素保存率无明显影响。红曲色素保存率随着光照时间的延长而降低,随着光照强度的增大而降低。在光照强度相同,单色光波长不同的条件下,红曲色素保存率由大到小依次为红光组>黄光组>绿光组>蓝光组>紫光组。红曲色素对短波紫外线较为敏感。在相同光照条件下,水溶性红曲色素光稳定性大于醇溶性红曲色素光稳定性。

Effects of illumination intensity(which was determined by quantifying the light absorbed using a luxmeter), wavelength and irradiation time on the preservation rate of Monascus pigments were examined. Sunlight(2 800–31 000 lx) caused the most serious photodegradation for monascus pigments whereas indoor natural light(54–2 050 lx) had relatively less serious effects, and no photodegradation was observed under dark condition(0 lx) The preservation rate of Monascuspigments was decreased with increasing illumination intensity and irradiation time. Under the condition of the same illumination intensity but different wavelengths, the preservation rate of Monascus pigments followed the decreasing order: red light > yellow light > green light > blue light > purple light. Monascus pigments were more sensitive to ultraviolet-C light. Under the same condition, water-soluble Monascus pigments were more stable than alcohol-soluble Monascus pigments.