The Exploitation Of Natural Food Plant Pigment Resources In Xinjiang--A Study Of The Pigment Of Althaea Rosea (L.) Cavan

This paper, based on the research to the petal of Althaea rosea (L.) Cavan of Xinjiang, attempts to exploit the utlity of this plant as a possible extractive material for the pigment products. By use of the theories and methods of many subjects, such as botany, plant chemistry, food hygiene and toxicology, the research involves the contrastive experiment to the extractive solvent, extractive time, extractive temperature and burden ration of material. The pigments are purified by silica gel chromatography. Furthermore, this research investigates preliminarily the extraction of the pigments with macroporous resin. The compositions of the pigments are determined initially by ultraviolet and visible light spectrum, acid-alkali reaction, hydrochloric acid-magnesium reaction, medium acetic lead sediment reaction and FeCl3 manifested colour reaction. The experiment studies also include the preliminary research of the effect of light, heat, PH value, oxide, reduant, fundamental materials of food, preservative, Vc and metal ions on the stability of the pigment. A kind of effective stability matter is selected. The crude components of the pigments are measured by use of the biochemical methods. The amounts of the contents of harm trace elements contained in the pigments, such as As, Hg, Pb, Cu, are determined by the method of atomic absorption spectrum. Then the edible-safety properties are examined by experiments of mice's acute toxicity. The experimental results indicate that the laboratory process is simple and easy to manage for extracting the red pigment of Althaea rosea (L.) Cavan by use of the organic solvents,and the pigment output ratio and comprehensive utilization are high. The red pigment is a type of anchocyanin which can be dissolved in water. It is strong in resisting light but poor in resisting oxide and reduant. To some extent, it is resistant to the temperature. This pigment presents the best colour when the PH value is less than five. It is also found in the experiments that the fundamental materials of food, preservative, Vc and some metal ions, such as Zn2+ Ca2+ K+ Na+, Al3+ and Mg2+ in lower concentration, do not exert negative effects on the stability of the pigment. While other metal ions,such as Fe3+ Fe2+ Cu2+ Pb2+ and Sn2+, have presented negative effects. By the test of harm trace elements and the experiment of acute toxicity, it is indicated that the red pigment has no toxicant and it can be safely used as the nature functional pigment.