Tel:Ģ 2098 Lestari et al./ifrj 24(5): no separation nature, spectroscopic techniques are unsuitable for analysis of individual curcuminoid in the extract of C. Near infrared and mid infrared spectroscopies are proposed for analysis of total curcuminoid and individual curcuminoid (Tanaka et al., 2008 Rohman et al., 2015). The wavelength of 420 nn is used by Pothitirat and Gritsanapan (2006) for total curcuminoid determination. UV-Vis spectroscopy has been used for analysis of curcuminoid, and the content of curcuminoid is expressed as total curcuminoid. Chromatographic and electrophoretic methods are time consuming and need skilful analyst, therefore some simple techniques based on spectroscopic technique is developed. Rohman (2012) has reviewed some methods used for determination of total and individual curcuminoid. xanthorrhizza such as high performance liquid chromatography with various detection systems like PDA and or UV (Jadhav et al., 2007 Wichitnithad et al., 2009), and UV-mass spectrometer detector (Li et al., 2011), thin layer chromatography (Paramasivam et al., 2009 Phattanawasin et al., 2009), capillary electrophoresis (Lechenberg et al., 2004), micellar electrokinetic chromatography (Watanabe et al., 2002 Unger et al., 2009). Several methods, especially based on chromatographic and electrophoretic techniques, have been developed and used for analysis of curcuminoid in C. Curcuminoid is believed to be responsible for some biological activities and is used as chemical marker in C. xanthorriza is a wellknown traditional medicine having some biological activities such as anti-inflammatory, antioxidant (Jantan et al., 2012), anticancer activities (Park et al., 2008), acetylcholinesterase inhibitors, as well as protective agents against neurodegenerative disorders (Zhang et al., 2015), anti-metastatic due to xanthorrhizol (Choi et al., 2005), antimicrobial activity (Mary et al., 2012), and hepatoprotective (Lin et al., 1996). All Rights Reserved Introduction One of the medicinal plant used popularly in Indonesia is Curcuma xanthorrhiza Roxb, or known as Temu lawak in Indonesia. It can be concluded that FTIR spectroscopy combined with PLS can be used as an alternative method to determine the curcuminoid content in C. Curcuminoid contents determined using FTIR spectroscopy combined with PLS were not statistically significant compared with method using independent sample t-test (P > 0.05). During PLS calibration, the R 2 values of calibration model and LOO for curcumin (C), demetoxycurcumin (DM) and total curcuminoid (TC) were > 0.99 with RMSEC, RMSECV and PRESS values were relatively small, whereas the R 2 values for external validation were 0.98 0.99 0.98, with RMSEP and PRESS values were relatively small for C, DM and TC, respectively. The wavenumbers selected ( cm -1 ) were relied on its capability to provide the correlation between the actual value and the predictive value of curcuminoid, indicated by the highest R 2 value with small PRESS and RMSEC values in the calibration model.
FTIR spectroscopy is validated by cross validation using leave-one-out (LOO) and external validation. xanthorrhiza were previously determined using with PDA detector. The actual contents of curcuminoid in the ethanolic extract of C. xanthorrhiza using FTIR spectroscopy combined with partial least squares (PLS). This research aims to analyze the content of curcuminoid (curcumin and demethoxycurcumin) in ethanolic extract of C. xanthorrhiza, the content of curcuminoid in the product must be properly determined. 3 Research Center of Halal Products, Gadjah Mada University, Yogyakarta, 55281, Indonesia Article history Abstract Received: 17 June 2016 Received in revised form: 17 September 2016 Accepted: 19 September 2016 Keywords Curcuma xanthorrhiza Roxb Curcuminoid FTIR spectroscopy Partial least square Curcuma xanthorrhiza Roxb (Temulawak) contains curcuminoid with various pharmacological effects. 1 Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Gadjah Mada University, Yogyakarta, 55281, Indonesia 2 The National Agency of Drug and Food Control, Republic of Indonesia. 1 International Food Research Journal 24(5): (October 2017) Journal homepage: Simultaneous analysis of Curcumin and demethoxycurcumin in Curcuma xanthorriza using FTIR spectroscopy and chemometrics 1,2 Lestari, H.P., 1 Martono, S., 1,2 Wulandari, R., and 1,3* Rohman, A.