Research of Extracting Pumpkin Yellow Pigment with Ultrasound-assisted Method

[Objective] The aim was to study the ultrasound-assisted method of pumpkin yellow pigment and compare it with leaching method so as to provide experimental foundation for exploiting and utilizing pumpkin.[Method] The ready solution of pumpkin yellow pigment was prepared by ultrasound-assisted method and its maximum absorption wavelength was determined by UV/VIS spectrophotometer Uv-250 in the wavelength range of 300～600 nm.With absorbance value of extracts at characteristic wavelength as index,the optimum extraction conditions were confirmed through single factor experiment and orthogonal experiment.[Result] The optimum conditions of extracting pumpkin yellow pigment with ultrasound-assisted method were as follows:with 95% ethanol as extraction solvent,ratio of material to liquid(g:ml) of 1:10,ultrasonic power of 80 W,extraction time of 40 min.Under the conditions,the crude yield of pigment was 10.6%.The maximum absorption wavelength of pumpkin yellow pigment was 446 nm.Among 3 factors of extracting pumpkin yellow pigment with ultrasound-assisted method,the R value of extraction time was largest,the next was that of ultrasonic power,and the least was that of ration of material to liquid.[Conclusion] Compared with leaching method,ultrasonic extraction had advantages of high efficiency,saving time and energy.