Optimizing of Pigments Extraction for Pulp of Hylocereus undatus ‘Hong Xian Mi'

The pigments of pitaya are natural dyes from plant with the characters of stable and wide in color gamut. The study was extracting red pigment from the pulp of pitaya to develop its comprehensive utilization.The pulp powder was prepared for extraction with freeze drying method and extracting procedure was optimized by single factor method,and then multi-factor orthogonal test.The results showed that,using 20% ethanol as extraction agent,the color in red solution was the brightest with the highest in absorbance.The acidity in the solution enhanced the pigment extraction;the maximum absorbance was observed while the temperature for extraction was at 40℃.The procedure of the optimum extraction was as extraction temperature 30℃,extraction time 45min,pH 6.5,and 30%ethanol concentration.The 4factors affected extraction differently,of which,extraction temperature was the key factor for controlling.