关键词: 宿晓红葡萄;色素;提取;稳定性

Abstract: This experiment explored the preferred method for the extraction of Suxiaohong grape pigment and the factors affecting pigment stability.The rape pigment was extracted with varying concentrations of ethanol,extraction period and temperature,and an orthogonal test was carried out to optimize the extraction process.The best extraction conditions were found to be: ethanol concentration,70%;extraction temperature,70℃;extraction time,60 minutes;and material to liquid ratio,1∶15.The factors influencing the stability of Suxiaohong grape pigment studied were light tolerance,redox resistance and acid and alkali resistance.The study showed that the pigment from Suxiaohong grape is stable in a strong acid environment of pH 1.0-4.0;the pigment is sensitive to light and will rapidly degrade under long-term exposure. Pigment stability can be maintained by adding a low concentration of Na2SO3,sodium benzoate and potassium sorbate preservative which has a certain color protection effect on pigments with high a concentration of citric acid and zinc ions.A better secondary color effect was achieved by adding Ca^2+ at a concentration of<1.0 mol/L and sucrose at a concentration of<20% to the pigment.

Key words: Suxiaohong grape;Pigment;Extraction;Stability