Abstract: The effects of extracting yellow pigment from Gardenia jasminoides Ellis by hot extraction, ultrasonic extraction and microwave-assisted extraction were compared. Orthogonal tests were used to optimize the conditions. Through orthogonal test of heat extraction, the optimum conditions were determined as follows:70% EtOH as extracting solvent, 2 h, 30℃, 1:25 solid-liquid ratio, the color value of the extracted pigment achieved 66.45.Through orthogonal test of ultrasonic extraction,the optimum conditions were determined as follows: 80% EtOH as extracting solvent,20 min at 20℃,and solid-liquid ratio 1:20, the color value of the extracted pigment achieved 87.77.Through single factor test of microwave-assisted extraction,the optimum conditions were determined as follows: 800 W, 50% EtOH as extracting solvent,30 min at 50℃,and solid-liquid ratio 1:5, the color value of the extracted pigment achieved 64.14. The results showed that the effects of extraction while by three different methods were different, ultrasonic extraction was the best way.

Key words: gardenia yellow pigment, extraction, colour value, OD ratio