文摘
The quality of turmeric products is directly based on the amount of curcumin. In this study, the Raman spectrum of curcumin was obtained to analyze curcuminoids in turmeric products quantitatively, particularly turmeric roots in powder form. The Raman band of sodium sulfite was used as an internal standard to remove the effect of several factors such as laser power and other instrumental parameters. Band intensity ratios (I 1,601/I 989 and I 1,630/I 989) were calculated for linear fitting. A calibration curve was generated by plotting the band ratio against sample concentration. Results showed that the band ratio between the Raman intensity of the samples and the internal standard exhibited good linearity with analyte concentration. This model was subsequently used to quantitatively analyze curcumin in different layers of turmeric roots, successfully confirming the ranges of curcumin weight ratio. Thus, the proposed method could be a convenient alternative to standard procedures used to determine the quality of turmeric roots.