药桑红色素稳定性研究

Study on Stability of Medicine Mulberry Red Pigment

研究了药桑红色素在不同环境下的稳定性,结果表明:药桑红色素具有较好的光稳定性,室外阳光直射下,3 d保存率仍在90%以上,在紫外光照射下不稳定,3 d衰减50%;对高温不稳定,在100℃时,放置8 h保存率即降低了40%,但在低温条件下较为稳定。色素对氧化剂不稳定,而在一定的还原剂条件下保存率仅略有降低;苯甲酸钠防腐剂对色素有护色作用;Fe3+、Fe2+和Ca2+可破坏色素水溶液稳定性,而其它金属离子对稳定性影响不明显。pH值增大至碱性范围会使色素稳定性降低,而在酸性条件下保存率较高。

The stability of medicine mulberry red pigment was investigated experimentally under different conditions.Results showed that the medicine mulberry red pigment was stable to sunlight with over 90% preservation rate after 3d,it was unstable to ultraviolet radiation with over 50% preservation rate declines after 3d.The medicine mulberry red pigment was stable to low temperature;it was unstable to high temperature with over 40% preservation rate declines after 8h.The pigment was unstable to oxidant,whose preservation rate declines slightly due to reducer.It is preserved on color by sodium benzoate.Except Fe3＋,Fe2＋,and Ca2＋,its stability in water solution is not interrupted by other metal ions.Alkaline pH significantly influences its stability,and the higher the pH value,the lower the stability,but under acid condition it has high preservation rate.