水溶性红曲黄色素的表征及其稳定性

CHARACTERIZATION AND STABILITIES OF WATER SOLUBLE MONASCUS YELLOW PIGMENT

以含硫化合物还原红曲色素,红斑素和红曲红素分子中的环羰基还原成羟基,得到水溶性红白曲黄色素.以 UV-Vis、IR和(?)H-^(13)CNMR对其结构进行了表征.该色素的吸光度随pH增大而略呈上升趋势,避光可明显提高其稳定性.除Mg^(2+)在pH9下使其溶液产生沉淀外,Sn^(2+)、Ca^(2+)、Fe^(3+)和AI^(3+)均不影响其稳定性.不同pH和温度下加热实验结果表明,酸性条件对其热稳定性影响较大.

The water soluble Monascus yellow pigment was prepared by reducing the cyclocarbonyl of monascorubrin and rubropunctatin to hydroxyl with sulphuric compounds. Its structure was characterized by UV-Vis,lR and 1H-13C NMR. The absorbance of the pigment was increased slightly with pH. Taking shelter from the light would improve its stability. The stability was not effected by Sn2+,Ca2+, Fe3+,and A13+, while precipitation was produced by Mg2+ under pH 9. The acid effect was more than other conditions in thermal stability under different pH and temperature.