Quantitative analysis of palm carotene using Fourier transform infrared and near infrared spectroscopy

beta-carotene content is usually determined by using ultraviolet (UV)-visib le spectrophotometry at 446 nm. In this study, two spectroscopic techniques , namely, Fourier transform infrared (FTIR) and near infrared (NIR) spectro scopy, have been investigated and compared to UV-visible spectrophotometry to measure the beta-carotene content of crude palm oil (CPO). Calibration c urves ranging from 200 to 800 ppm were prepared by extracting beta-carotene from original CPO using open-column chromatography. Separate partial least squares calibration models were developed for predicting beta-carotene bas ed on the spectral region from 976 to 926 cm(-1) for FTIR spectroscopy and 546 to 819 nm for NIR spectroscopy. The correlation coefficient (R-2) and s tandard error of calibration obtained were 0.972 and 25.2 for FTIR and 0.95 2 and 23.6 for NIR techniques, respectively. The validation set gave R-2 of 0.951 with standard error of performance (SEP) of 25.78 for FTIR technique and R-2 of 0.979 with SEP of 19.96 for NIR technique. The overall reproduc ibility and accuracy did not give comparable results to that of spectrophot ometric method; however, the standard deviation of prediction was still wit hin +/- 5% beta-carotene content over the range tested. Because of their ra pidness and simplicity, both FTIR and NIR techniques provide alternative me ans of measuring beta-carotene content in CPO. In addition, these two spect roscopic techniques are environmentally friendly since no solvent is involv ed.