蓝粒和紫粒小麦色素稳定性的研究

Pigment's Stability in Grains of Wheat with Blue Grain or Violet Grain

为了进一步开发利用蓝粒小麦和紫粒小麦的商业价值,以蓝粒小麦和紫粒小麦麸皮的乙醇浸提色素溶液(pH=2)为材料,分析了蓝、紫粒小麦色素的光谱特性以及pH、温度、自然光、氧化剂(H2O2)、还原剂(Na2SO3和Vc)、防腐剂(苯甲酸钠)和食品饮料添加剂(柠檬酸、食盐、蔗糖等)以及常见金属离子Fe2+、Ca2+、Zn2+、Mg2+、Al3+、Cu2+、Fe3+等对两类小麦色素稳定性的影响。光谱特性分析表明,在可见光区,蓝粒小麦和紫粒小麦色素酸性乙醇溶液的最大吸收波长分别为530 nm和520 nm。研究还表明,蓝、紫粒小麦色素溶液的颜色均与pH有关,pH越小颜色越鲜艳,在pH≤3时蓝粒和紫粒小麦色素酸性乙醇溶液分别具有稳定的紫红色和棕红色;蔗糖、食盐、热、还原剂对蓝、紫粒小麦色素的影响很小;除Cu2+、Fe3+外,其它常见金属离子均对蓝、紫粒色素无影响;蓝、紫粒小麦色素对于光、氧化剂的抗性不同,蓝粒色素比较抗氧化,紫粒色素比较抗光照。

In order to develop and utilize further commercial value of wheat with blue grain or violet grain, the pigment solution （pH=2） was extracted from the bran of wheat with blue grain or violet grain by 70% ethanol, the pigment＇s spectrum properties was studied. The pigment＇s stability of two kinds of wheat were under different treatments of pH, temperature, natural light, oxidants （H2O2）, reducing agents （Na2SO3 and Vitamin C）, preservatives（sodium benzoate）, food or beverage additives （citric acid, salt, sucrose, etc. ） and common metal ions （Fe^2＋ , Ca^2＋ , Zn^2＋ , Mg^2＋ , Al^3＋ , Cu^2＋ , Fe^3＋ , etc）. The results showed that the maximal absorbtion wave length of blue-grain wheat and violet-grain wheat were 530nm and 520nm in the visible light range, respectively. The pH value of the pigment solution had effects on the stability of pigment. The pH was smaller and the color of the pigment solution was brighter. The pigment＇s colour of blue-grain wheat and violet-grain wheat were purple-red and brown-red in pH≤3, respectively. Sucrose, salt, heat and preservatives had very little significant effects on the pigment stability. Compared with Cu^2＋ and Fe^3＋ , the other common metal ions had no significant effects on the pigment stability. The pigment solution of the blue-grain and violet-grain wheat had different resistance to natural light and oxidants. The pigment solution of the blue-grain wheat was more resistant to oxidants than that of the violet-grain wheat and the pigment solution of the violet-grain wheat was more resistant to natural light than that of the blue-grain wheat.