Studies On The Extraction And Properties Of Pigments From Aspergillus Ochraceus405

Aspergillus ochraceus405produced red pigment during the11α-hydroxylation reaction system, which contains some natural pigments. The extraction, isolation and properties such as stability of the pigment were carried out.This study established the extraction and isolation methods of A. ochraceus pigment, which was composed of four kinds of components, yellow, orange and two claret pigments. The optimum extraction conditions, from the single factor extracting experiments and orthogonal experiment, were the optimal organic solvent was ethyl acetate, the optimal time was20min, the optimal ratio of gardenia to liquor was1:40(m/v) and the optimal extracting grade was fourth grade with the extraction rate99.33%.Petroleum ether-acetone system and chloroform-methanol system were determined by thin-layer chromatography method as the elution systems of column chromatography. Gradient elution rates were5:1,1:1,0:1and400:1,100:1,0:1and400:1,200:1,40:1,0:1. Finally it was separated by gel column chromatography, methanol for the eluting agent. The pigment was composed of4kinds of pigments:yellow, orange, claret1and claret2.3.5mg claret pigment1,8.7mg orange pigment and31.6mg claret pigment2were got. The structure of the orange pigment carried out by chemical analysis, UV and FTIR was p-benzoquinone.In this experiment, the effect of temperature, acid, alkali, light and other factors on the stability of claret pigment2was studied. The results showed that acid and alkali affected the stability of the pigment at varying degrees, which was stable at pH6-8. The pigment was stable at room temperature to40℃in12h but it would still depigment with times went by. It was more stable in the room beam than that in the outdoor, and that the addition of metal ions and oxidizing or reducing agent would have various degree of effect on its stability.Two methods, reducing K3Fe(CN)6to determin the reducing force and oxidizing a-deoxyribose to determin the ability to clear the hydroxyl radical, were used to study the antioxidant ability of claret pigment2. The results showed that when the concentrations of the claret pigment and α-tocopherol were0.1-0.9mg/mL, the absorbances at700nm of them ware0.486-1.239and0.354-1.110. The reducing force of the pigment2increased with its concentration. The hydroxyl radical scavenging abilities of them were6.85-41.02%and2.35-39.52%.The hydroxyl radical scavenging ability of the pigment2increased with its concentrations and was lower than that of a-tocopherol.