Savolainen K, Kuusi T
Z Lebensm Unters Forsch. 1978 Jan 31;166(1):19-22. doi: 10.1007/BF01122999.
Golden beet (Beta vulgaris var. lutea) color was found to contain 8 components, of which the most important seemed to be vulgaxanthin-I and -II. Purified vulgazanthin -I solutions are easily degraded at high temperatures. The stability is, however, strongly dependent on pH: the stability is best at pH values between 5 and 6, the poorest at low pH values, but at pH 7 the stability is better than that of betanin. Vulgaxanthin-I is more stable in the raw extract than in a purified solution. EDTA, even in ppm amounts, was found to improve the stability of betanin. The effect was dependent on pH value, being most efficient at pH 2.0 and 5.0. Stability of vulgaxanthin-I was not improved by EDTA. Tannin did not show stabilizing influence. Ascorbic acid was found to have an unfavorable influence on stability, especially in the case of betanin.
人们发现金色甜菜（Beta vulgaris var. lutea）色素含有8种成分，其中最重要的似乎是紫黄质-I和紫黄质-II。纯化的紫黄质-I溶液在高温下容易降解。然而，其稳定性在很大程度上取决于pH值：在pH值为5至6时稳定性最佳，在低pH值时最差，但在pH值为7时，其稳定性优于甜菜红。紫黄质-I在粗提取物中比在纯化溶液中更稳定。人们发现，即使是百万分之一含量的乙二胺四乙酸（EDTA）也能提高甜菜红的稳定性。这种效果取决于pH值，在pH值为2.0和5.0时最有效。EDTA并未提高紫黄质-I的稳定性。单宁未显示出稳定作用。人们发现抗坏血酸对稳定性有不利影响，尤其是对甜菜红而言。
