Objective: To study content changes of index compositions from Gardeniae Fructus in microwave processing and its correlations with powder color changes

in order to provide scientific basis for quality assessment of its microwave processed products. Method: HPLC was employed to determine the contents of genipin-1-β-D-gentiobioside

geniposide

crocin-Ⅰ

crocin-Ⅱ and crocin-Ⅲ with mobile phase of acetonitrile-water (containing 0.2% phosphoric acid) for gradient elution and detection wavelengthes of 238

440 nm.The content of total tannin was measured by UV at 760 nm.The correlations between contents of these components and color quantization parameters (L

a and b) were analysed. Result: With the increase of microwave processing time

the temperature gradually increased

the contents of geniposide

crocin-Ⅰ and crocin-Ⅱ decreased;the contents of genipin-1-β-D-gentiobioside and crocin-Ⅲ increased slightly at the beginning

and gradually reduced when the temperature exceeded 200 ℃;the content of total tannin increased gradually and reached the highest at 5 min

and then decreased rapidly.The content of geniposide was positively correlated with L

the content of crocin-Ⅰ was positively correlated with a and b. Conclusion: There are correlations between the contents of index components and powder color changes in microwave processing of Gardeniae Fructus.