Optimization of enzyme-assisted extraction technology ofpigment from black carrot by response surface methodology

To optimize the cellulase-assisted extraction process of pigment from black carrot，dried powder of blackcarrot was used as material，on the base of single factor test，response surface methodology was used to investigate theeffects of processing parameters，including ratio of liquid to material，pH value，and extraction time on the extraction rateof pigment，and mathematical model was established by implementing three factors and three levels. The regression modelwas highly significant，and the established regression equation for the extraction rate of pigment had excellent goodnessof fit，therefore the pigment from black carrot could be analyzed and predicted by the model. Factors influencing theextraction of pigment from black carrot were in the order as follows：extraction numbers > pH value > ratio of liquid tomaterial. The quadratic term also reached great difference. But the response surface plots showed that the interactionamong each factor was not significant. When the cellulase concentration was 0.5% and temperature was 50℃，theoptimum conditions were as follows：30∶1 of the ratio of liquid to material，3.9 of pH value，2 of extraction times. Theextraction rate of pigment from black carrot was up to 0.9485 mg/g，which was highly consistent with the predictive valueof 0.9508 mg/g.