Application of FTIR and NIR Spectroscopy Coupled with Chemometrics for Determination of Monosodium Glutamate Level in Balado Seasoning

Abstract

Balado seasoning is a spicy powder containing chili, spices and monosodium glutamate (MSG). MSG is a natural monosodium salt in the form of L-glutamic acid, used as a savory taste in food. This study aims to determine MSG in Balado seasoning using near-infrared (NIR) and Fourier transform infrared (FTIR) spectroscopy methods combined with hemometrics. The comparison method used was the thin layer chromatography (TLC)-Densitometry method. Support Vector Regression (SVR), Principal Component Regression (PCR) and Partial Least Square (PLS) were used to form a calibration model. Then the selected calibration model was validated by the leave one out cross validation (LOOCV) and external validation methods. Based on the research result, the PLS model is the selected calibration model with both the NIR and FTIR methods which gives the best results with an R2 value > 0.91. The results of the LOOCV validation have met the parameter values of R2 > 0.91, and the external validation result using the NIR and FTIR methods yielded R2 values of 0.999 and 0.997 and RMSEP value of 0.093 and 0.284, respectively. The concentration of MSG in commercial samples obtained by TLC Densitometry as a reference method were 1.314%, 1.449%, 5.836%, and 9.672%. The results of the analysis of MSG concentration as measured by the NIR and FTIR spectroscopy compared to TLC Densitometry did not give a significant difference.