Study On Extraction And Purification Of Gardenia Yellow And Stability Of The Pigment

This paper mainly dealt with the extraction and purification conditions of gardenia yellow and stability of the colorant. The study laid theoretical foundation for large-scale extraction and purification of gardenia yellow. Through experiments, the optimum extraction conditions of ethanol extraction and microwave extraction were obtained. The optimum conditions of ethanol extraction were ethanol/water (6:4), extraction time lh at 500C, gardenia fruit solvent =1:12. As a result, the yield and the color value of the extracted pigment achieved 92.10% and 50.50, respectively. The optimum conditions of microwave extraction were ethanol/water (5:5), extraction time 8s, extraction power 210W. As a result, the yield and the color value of the extracted pigment achieved 98.24% and 56.94, respectively. The optimum purification conditions of gardenia yellow by macroporous resin adsorption were studied. While 1 .5m1/min as the flow rate on adsorption, 2.5m1/min as the flow rate on desorption and stepwise elution were adopted, the A2381A440 was lowed to 0.59 from 2.12, the recovery was up to 88.80%, and colourity was 218.12. This paper also reported the optimum purification conditions of gardenia yellow by gel filtration chromatography. The A238/A440 was less than 0.20, the product rate was 48.91%, colourity was 218.12. The pigment was sensitive to acid , oxidant and Fe2 Cu2. This paper has proved that the pigment maintain stable under protection of glucose, sucrose and lactose. Meanwhile, the pigment showed heat- stability, preserve-stability and high-colored capacity in beverage, frozen foods and milk products.