Abstract-Detection of Melamine in Foods using Terahertz Time-domain Spectroscopy

Seung Hyun Baek , Heung Bin Lim , and Hyang Sook Chun

http://pubs.acs.org/doi/abs/10.1021/jf501170z

J. Agric. Food Chem., Just Accepted Manuscript

DOI: 10.1021/jf501170z

Publication Date (Web): June 2, 2014

Copyright © 2014 American Chemical Society

The aim of this study was to investigate the feasibility of detecting melamine in foodstuffs using terahertz imaging. The terahertz (THz) spectra and images of melamine mixtures were obtained in the frequency range of 0.1–3 THz at room temperature using THz time-domain spectroscopy. Characteristic absorption peaks of melamine were found at 2, 2.26, and 2.6 THz, and these peaks showed the same frequencies in the different food matrices. At 2 THz, the THz images of melamine were dose-dependently distinguishable from those of food components with or without the packaging materials used. The calibration curve of melamine showed a regression coefficient (R2) of > 0.913 and detection limit of < 13%. These results suggest that terahertz imaging has the potential to be used for the qualitative detection of melamine in food as a nondestructive analytical tool.

Abstract-High-speed terahertz imaging toward food quality inspection

Gyeongsik Ok, Kisang Park, Hyun Jung Kim, Hyang Sook Chun, and Sung-Wook Choi  
»View Author Affiliations

Applied Optics, Vol. 53, Issue 7, pp. 1406-1412 (2014)
http://dx.doi.org/10.1364/AO.53.001406

http://www.opticsinfobase.org/ao/abstract.cfm?uri=ao-53-7-1406

In contrast to conventional x-ray food inspection systems that have difficulty in detecting low-density materials, a terahertz imaging system can even identify insects and plastics embedded in a food matrix. A reflection-mode continuous-wave terahertz imaging system was therefore developed for application to food quality inspection, which requires fast, compact, and low-cost detection. High-speed operation of the terahertz imaging system was achieved through the use of a beam-steering tool. A reasonable compromise between the spatial resolution and the scan length of an aspheric f-theta scanning lens could be achieved by optimizing the lens parameters.

© 2014 Optical Society of America

Abstract-High-speed terahertz imaging toward food quality inspection

                         Gyeongsik Ok, Kisang Park, Hyun Jung Kim, Hyang Sook , and Sung-Wook Choi

received 12/06/2013; accepted 01/27/2014; posted 01/28/2014; Doc. ID 202672

http://www.opticsinfobase.org/ao/upcoming_pdf.cfm?id=202672

In contrast to conventional X-ray food inspection systems that have difficulty detecting low-density materials, a terahertz (THz) imaging system can even identify insects and plastics embedded in a food matrix. A reflection mode continuous-wave THz imaging system was therefore developed for application in food quality inspection, which requires fast, compact, and low-cost detection. High-speed operation of the THz imaging system was achieved through the use of a beam-steering tool. A reasonable compromise between the spatial resolution and the scan length of an aspheric f-theta scanning lens could be achieved by optimizing the lens parameters.