Optimization Of Extraction Technology And Stability Studies For Pigment From Citrus

This paper improve ultrasonic extraction technology, microwave extraction technology and supercritical CO2 extraction technology to get the best process of extracting pigment from citrus peels with response surface methodology, and conduct the stability studies of extracted pigment. It is aimed at providing a theoretical basis and practical application for the production of pigment from citrus peels. The main conclusions are as follows:(1) The result with raw material of over 80 by using ultrasonic assisted extraction method and microwave-assisted method are better, and the result with raw material of over 60 by using supercritical CO2 extraction method is better; It is economical and practical to choose ethanol as a solvent of extraction.(2) The conditions to obtain optimum result by using optimization of ultrasonic extraction technology for pigment from citrus peels by response surface methodology:liquid ratio of 1:9 (g/ml), ultrasonic power 300W, extraction time 17 min, extraction temperature was 79 ℃. The extraction of pigment from citrus peels is the best under this condition. This measured absorbance value of pigment from citrus peels is 0.874.(3) The conditions to obtain optimum result by using optimization of microwave extraction technology for pigment from citrus peels by response surface methodology:liquid ratio of 1:9 (g/ml), ultrasonic power 240W, extraction time 6 min. The extraction of pigment from citrus peels is the best under this condition. This measured absorbance value of pigment from citrus peels is 0.765.(4) The conditions to obtain optimum result by using optimization of supercritical CO2 extraction technology for pigment from citrus peels by response surface methodology:citrus peel crush size of 60 mesh, taking pressure of 25Mpa, CO2 flow rate of 13 L/h, extraction temperature 35 ℃, extraction time 3.35 h. The extraction of pigment from citrus peels is the best under this condition. This measured yield of pigment from citrus peels is 6.29%.(5) Studies on stability of pigment from citrus peels:pigment from citrus peels soluble polar organic solvent molecules, and also soluble in non-polar solvent molecules, and further soluble in water. pigment from citrus peels is natural light-sensitive indoor, not light, and suitable for preservation in the darkroom; pH values have a great impact on the pigment from citrus peels, especially acid and alkali, relatively speaking, acid ratio has a greater impact on the stability of the pigment compared to alkali; temperature have some influence on pigment from citrus peels, but have little effect under conditions of lower than 70 ℃; Na+(Na2SO4), Ca2+(CaCl2), K+(KCI), Mg2+(MgCl2), Mn2+(MnCl2) ions have few impact on stability of pigment from citrus peels, which can be negligible; food additives, such as glucose, sucrose have little impact on the stability of pigment from citrus peels, citric acid has some damaging effects on the stability of pigment from citrus peels; pigment from citrus peels have poor oxidation resistance of and the content of oxidant is high, have a great impact on the stability of the pigment. on The pigment from citrus peels has a strong citrus peel resistance reduction and can be applied simultaneously in food processing with reducing agent.