Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System
Curry powder is extensively used in Southeast Asian dishes. It has been subject to adulteration by azo dyes. This study used a newly developed 1064 nm dispersive point-scan Raman system for detection of metanil yellow and Sudan-I contamination in curry powder. Curry powder was mixed with metanil yel...
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MDPI AG
2018-04-01
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| Series: | Applied Sciences |
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| Online Access: | http://www.mdpi.com/2076-3417/8/4/564 |
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| author | Sagar Dhakal Kuanglin Chao Walter Schmidt Jianwei Qin Moon Kim Qing Huang |
| author_facet | Sagar Dhakal Kuanglin Chao Walter Schmidt Jianwei Qin Moon Kim Qing Huang |
| author_sort | Sagar Dhakal |
| collection | DOAJ |
| description | Curry powder is extensively used in Southeast Asian dishes. It has been subject to adulteration by azo dyes. This study used a newly developed 1064 nm dispersive point-scan Raman system for detection of metanil yellow and Sudan-I contamination in curry powder. Curry powder was mixed with metanil yellow and (separately) with Sudan-I, at concentration levels of 1%, 3%, 5%, 7%, and 10% (w/w). Each sample was packed into a nickel-plated sample container (25 mm × 25 mm × 1 mm). One Raman spectral image of each sample was acquired across the 25 mm × 25 mm surface area. Intensity threshold value was applied to the spectral images of Sudan-I mixtures (at 1593 cm−1) and metanil yellow mixtures (at 1147 cm−1) to obtain binary detection images. The results show that the number of detected adulterant pixels is linearly correlated with the sample concentration (R2 = 0.99). The Raman system was further used to obtain a Raman spectral image of a curry powder sample mixed together with Sudan-I and metanil yellow, with each contaminant at equal concentration of 5% (w/w). The multi-component spectra of the mixture sample were decomposed using self-modeling mixture analysis (SMA) to extract pure component spectra, which were then identified as matching those of Sudan-I and metanil yellow using spectral information divergence (SID) values. The results show that the 1064 nm dispersive Raman system is a potential tool for rapid and nondestructive detection of multiple chemical contaminants in the complex food matrix. |
| first_indexed | 2024-12-21T18:52:06Z |
| format | Article |
| id | doaj.art-58e3398282d34a619cda44de08d3860b |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-12-21T18:52:06Z |
| publishDate | 2018-04-01 |
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| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-58e3398282d34a619cda44de08d3860b2022-12-21T18:53:43ZengMDPI AGApplied Sciences2076-34172018-04-018456410.3390/app8040564app8040564Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman SystemSagar Dhakal0Kuanglin Chao1Walter Schmidt2Jianwei Qin3Moon Kim4Qing Huang5United States Department of Agriculture/Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, Bldg. 303, Beltsville Agricultural Research Center East, 10300 Baltimore Ave., Beltsville, MD 20705-2350, USAUnited States Department of Agriculture/Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, Bldg. 303, Beltsville Agricultural Research Center East, 10300 Baltimore Ave., Beltsville, MD 20705-2350, USAUnited States Department of Agriculture/Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, Bldg. 303, Beltsville Agricultural Research Center East, 10300 Baltimore Ave., Beltsville, MD 20705-2350, USAUnited States Department of Agriculture/Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, Bldg. 303, Beltsville Agricultural Research Center East, 10300 Baltimore Ave., Beltsville, MD 20705-2350, USAUnited States Department of Agriculture/Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, Bldg. 303, Beltsville Agricultural Research Center East, 10300 Baltimore Ave., Beltsville, MD 20705-2350, USAChinese Academy of Sciences (CAS), 350 Shushanhu Road, P.O. Box 1138, Hefei 230031, ChinaCurry powder is extensively used in Southeast Asian dishes. It has been subject to adulteration by azo dyes. This study used a newly developed 1064 nm dispersive point-scan Raman system for detection of metanil yellow and Sudan-I contamination in curry powder. Curry powder was mixed with metanil yellow and (separately) with Sudan-I, at concentration levels of 1%, 3%, 5%, 7%, and 10% (w/w). Each sample was packed into a nickel-plated sample container (25 mm × 25 mm × 1 mm). One Raman spectral image of each sample was acquired across the 25 mm × 25 mm surface area. Intensity threshold value was applied to the spectral images of Sudan-I mixtures (at 1593 cm−1) and metanil yellow mixtures (at 1147 cm−1) to obtain binary detection images. The results show that the number of detected adulterant pixels is linearly correlated with the sample concentration (R2 = 0.99). The Raman system was further used to obtain a Raman spectral image of a curry powder sample mixed together with Sudan-I and metanil yellow, with each contaminant at equal concentration of 5% (w/w). The multi-component spectra of the mixture sample were decomposed using self-modeling mixture analysis (SMA) to extract pure component spectra, which were then identified as matching those of Sudan-I and metanil yellow using spectral information divergence (SID) values. The results show that the 1064 nm dispersive Raman system is a potential tool for rapid and nondestructive detection of multiple chemical contaminants in the complex food matrix.http://www.mdpi.com/2076-3417/8/4/564Raman chemical image1064 nmself-modeling mixture analysisfood safetycurry powderazo dyes |
| spellingShingle | Sagar Dhakal Kuanglin Chao Walter Schmidt Jianwei Qin Moon Kim Qing Huang Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System Applied Sciences Raman chemical image 1064 nm self-modeling mixture analysis food safety curry powder azo dyes |
| title | Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System |
| title_full | Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System |
| title_fullStr | Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System |
| title_full_unstemmed | Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System |
| title_short | Detection of Azo Dyes in Curry Powder Using a 1064-nm Dispersive Point-Scan Raman System |
| title_sort | detection of azo dyes in curry powder using a 1064 nm dispersive point scan raman system |
| topic | Raman chemical image 1064 nm self-modeling mixture analysis food safety curry powder azo dyes |
| url | http://www.mdpi.com/2076-3417/8/4/564 |
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