FOURIER TRANSFORM INFRARED SPECTROSCOPY AND CHEMOMETRICS FOR AUTHENTICATING CHILI POWDER FROM RHODAMINE B, ERYTHROSINE B, AND PARARED

Objective: The purpose of this study was to identify chili powder adulteration with synthetic dyes of rhodamine B, erythrosine B, and parared using Fourier Transform Infrared (FTIR) spectroscopy and chemometrics. Methods: The analysis included two types of red chilies, curly red and big red chilies. FTIR and chemometric spectroscopy combination were used to detect synthetic dyes in the chili powders. Principal Component Analysis (PCA), Partial Least Square-Discriminant Analysis (PLS-DA), and Partial Least Square-Regression (PLS-R) methods were applied. Results: The FTIR spectrum in the range of 700-850, 1100-1700, and 2300-3500 cm-1 can detect the adulteration of chili powder with rhodamine B or erythrosine B. Meanwhile, the parared dye can be distinguished at wave numbers of 2000-3000 cm-1. Conclusion: The combination of FTIR spectroscopy with chemometrics can be used to authenticate red chili powder from rhodamine B, erythrosine B, and parared.