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Raman and IR spectroscopic modality for authentication of turmeric powder
Kuanglin Chao1, Sagar Dhakal1, Walter F Schmidt1
1Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Avenue, Bldg. 303 BARC-East, Beltsville, MD 20705, USA.
Food Chemistry
|March 24, 2020
Summary
Detecting food adulterants like Sudan Red and white turmeric in powders is crucial. Infrared (IR) spectroscopy proved effective for quantitative analysis, outperforming Raman imaging in this study.
Area of Science:
- Food Science
- Analytical Chemistry
- Spectroscopy
Background:
- Chemical contamination of food powders is a significant global food safety issue.
- Accurate detection methods are essential to ensure food integrity and consumer safety.
Purpose of the Study:
- To evaluate Raman imaging and FT-IR spectroscopy for detecting Sudan Red and white turmeric adulteration in turmeric powder.
- To compare the effectiveness of Raman and IR spectroscopy in quantitative analysis of adulterants.
Main Methods:
- Raman imaging and Fourier-transform infrared (FT-IR) spectroscopy were employed.
- Spectral data were analyzed to identify unique peaks for adulterants.
- Partial least squares regression models were developed using IR spectra for quantification.
Main Results:
- Raman imaging showed limitations, including false positives for Sudan Red and unidentifiable peaks for white turmeric.
- FT-IR spectroscopy successfully identified discrete peaks for both Sudan Red and white turmeric.
- IR-based regression models accurately estimated Sudan Red (R=0.97) and white turmeric (R=0.95) concentrations.
Conclusions:
- FT-IR spectroscopy is a reliable method for detecting and quantifying Sudan Red and white turmeric in turmeric powder.
- Developing integrated IR and Raman imaging systems could enhance simultaneous detection of food adulterants.
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