中文摘要：

从工业发酵生产井冈霉素的吸水链霉菌5008发酵液中提取了一种黑色素,采用光谱法研究了光、温度、p H、还原剂、氧化剂、金属离子和食品添加剂对该色素稳定性的影响,并进行红外光谱分析,初步推测该色素的结构。结果表明：该色素具有较好的光、热稳定性和抗紫外辐射能力,具有一定的抗氧化性和抗还原性;p H值对该色素影响较明显,强酸性条件下色素会产生沉淀并变色,中、碱性条件下较稳定;Ca2＋、Mn2＋、Fe3＋对色素的影响较大,Al3＋能够对色素起到保色作用,而Mg2＋、K＋、Na＋对色素影响较小;常见食品添加剂蔗糖和葡萄糖能增加色素稳定性,碳酸氢钠、苯甲酸钠对色素稳定性影响较小,柠檬酸对色素影响较大。红外光谱图表明,该色素的基本结构单元可能是吲哚环。该研究对工业发酵中的副产物加以充分利用,为天然色素的开发提供了理论依据和可能性。

英文摘要：

A melanin was extracted from the fermentation supernatant of Streptomyces hygroscopicus 5008 which was used for VaI-A fermentation in industry. Its stability to sunlight, ultraviolet light, temperature, pH valve, hydrogen peroxide （H202） as an oxidant, Vc as a deoxidizer, sucrose, glucose, sodium benzoate and metal ions was evaluated. And infrared spectrum analysis was taken to speculate the preliminary structure of the pigment. Results showed that the melanin exhibited strong tolerance to sunlight and radiation and it had good heat stability and certain oxidation and reducing resistance. pH exerted a large effect on the pigment stability. It would precipitate and became dark claret-red in strong acid condition and it was stable in neutral and alkaline solution. Ca2＋, Mn2＋ and Fe3＋ affected the pigment much more than Mg2＋, K＋ and Na＋, while Al3＋ could protect its color. The melanin was stable to food additives such as glucose, sucrose, dicarbonate and sodium benzoate, while citric acid could make the pigment precipitate. In addition, according to the infrared spectrogram of melanin, we speculated its elementary structure was indole ring. This study made the most of the fermentation product of Streptomyces hygroscopicus 5008 and provided theory basis and possibility for the development of a natural pigment.