红叶甜菜红色素的稳定性研究

采用80% 乙醇为提取溶剂，将提取的色素液在230～700nm 范围内进行紫外扫描，而后分别探讨碳水化合物、pH 值、温度、氧化剂还原剂、光照、金属离子对色素在紫外和可见光区的稳定性的影响。结果表明：该色素在紫外光区有两个吸收峰，波长分别为270、334nm，可见光区有两个吸收峰，波长分别为538、666nm；红叶甜菜红色素对热比较稳定，但不耐高温；pH 值对色素颜色影响不是很大，除pH10 以外；碳水化合物对其影响不显著；其抗氧化能化较弱；自然光照射一定时间会褪色；大多数金属离子对其无影响；而Fe3+ 等少数金属离子对色素有影响。

Stabilization of Red Pigments from Edible-leaf Beet (Beta vulgaris var. cicla) Stems

The red pigments that were extracted from edible-leaf beet stems using 80% ethanol were subjected to spectral scanning in the wavelength range of 230－700 nm, and the influences of sucrose, pH value, temperature, reducer, oxidizer, light and metal ions on the stability of the red pigments were investigated. The results showed that the pigments had two peaks in the UV region, which were at 270 nm and 334 nm, respectively, and also had two peaks at 538 nm and 666 nm in the visible light region. The red pigments from edible-leaf beet stems was stable when heated for 30 min below 70 ℃, but it could not resist high temperature; the color of the red pigments was stable when pH was below 10; the pigments presented weak antioxidant capacity, and the color would fade when exposed to the natural light for a long time, while sugar had no obvious effect on it; and other metal ions such as Ca2+, Mg2+ and Zn2+ had no effects on it, except Fe3+ and Al3+ exhibiting hypochromic effect, while K+ and Na+ presenting hyperchromic effect.