Abstract: Glucomannoglycan gum extracted from Blitilla striata was studied on the compatibility in the O/W Pericarpium zanithoxyli essential oil emulsifying system which contains Tween 60, Span 20 with glycerol monostearate as emulsifier and glucomannoglycan gum as emulsion stabilizer. The photomicrographs of different emulsions acquired by the phase contrast microscope were analyzed by pixels gradation. Based on the histograms and their standard deviation, central values and mean values,the emulsions particle dispersion was evaluated. Then, according to the results of stability tests, standard deviation of the histogram could be an evidence for excluding a type of emulsion prescription during screening period. The method can increase screening efficiency.

Key words: Blitilla striata, glucomannoglycan gum, Pericarpium zanithoxyli essential oil, emulsifier, histogram