Abstract:

Yellow pigment was extracted from orange peels with the method of microwave extraction. The single-factor experiments were used to investigate the effects of particle size, the microwave output power, the microwave extraction irradiation time, ratios of solution to solid and alcohol concentration on absorbance. On the basis of single-factor experiments, a quadratic polynomial regression equation of the forecasting model was set up with Box-Behnken design of three factors and three levels. The optimal conditions of microwave extraction were concluded as follows: particle size 0.198 mm, ratios of solvent to material 1:15 (g/mL), alcohol concentration 88%, microwave output power 250 W, microwave extraction irradiation time 500 s. The yield was 14.12%. The pigments were yellow and contained carotenoids and flavonoids.