Nondestructive determination of curcuminoids from turmeric powder using FT-NIR

Nondestructive method of measuring curcuminoid content of turmeric powder was developed by fourier transform near infrared (FT-NIR) spectrometer. Also, the calibration models describing the relationship between curcuminoid content and the NIR spectra of the turmeric powder were developed and evaluated. To develop the model, NIR reflectance spectra were acquired for each turmeric powder sample. Spectra were pre-processed by applying different spectra correction algorithms. The relationship between spectrometric curcuminoid content and FT-NIR spectra of turmeric powder was examined through partial least square (PLS) regression method in the wave number range of 6102 to 4246 cm(-1). The root mean square error of cross-validation and test set validation were 0.104 and 0.201 whereas the determination coefficient (R(2)) for both the validations were 97.64 and 87.53, respectively. A low value of root mean square error and high value of R(2) indicates a high correlation between the concentration and spectral data. Thus the FT-NIR offers a viable alternative to spectroscopic procedures as well as the method is time and cost effective for determination of curcuminoid content of turmeric.