Food inspection using high performance quantum cascade laser

Food inspection techniques are essential to address food safety issues. In this paper, based on a more systematic review of commonly used food inspection techniques, a special study on edible oil safety testing techniques is conducted. Through an extensive review of the literature, the author conclu...

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Main Author: He, Yuzhi
Other Authors: Wang Qijie
Format: Thesis-Master by Coursework
Language:English
Published: Nanyang Technological University 2022
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Online Access:https://hdl.handle.net/10356/157730
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1577302023-07-04T17:48:22Z Food inspection using high performance quantum cascade laser He, Yuzhi Wang Qijie School of Electrical and Electronic Engineering qjwang@ntu.edu.sg Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics Food inspection techniques are essential to address food safety issues. In this paper, based on a more systematic review of commonly used food inspection techniques, a special study on edible oil safety testing techniques is conducted. Through an extensive review of the literature, the author concluded that the late start of mid-infrared spectroscopy has strong advantages for food safety testing. According to the actual situation, edible oil is used as the experimental samples in this dissertation. The experimental equipment includes FTIR (Fourier Transform infrared spectroscopy), QCL (Quantum Cascade Laser), DAQ (Data Acquisition) and Lock-in amplifier. FTIR measures the complete spectrum of edible oil; QCL measures the characteristic absorption peaks in part of the spectrum of edible oil; DAQ can be used to acquire data. The Lock-in amplifier can extract weak signals from the noise and measure them accurately. The purpose of the experiments was to measure the spectra of different edible oils and then compare their absorption peaks as well as bandgap to determine their difference. In the experiment, the author first measured the olive oil and sun flower oil using FTIR, and selected the absorption peak (960-1300cm-1) from the spectrogram that is suitable for further measurement using QCL.The QCL experiment part includes two steps, one is to obtain the appropriate oil film thickness to ensure the spectrogram effect, and the other is to obtain the absorption peaks of various edible oils as well as bandgap for comparative analysis to determine the differences of the oils. The authors believe that the appropriate oil film thickness is very important for the measurement to obtain the spectrogram of the ideal absorption peak. If the oil film is too thick, the laser penetration is not enough to pass through; if the oil film is too thin, the spectrogram will show interference phenomenon, so the first step is to obtain the appropriate oil film thickness by adding spacer. After determining the film thickness, the absorption peak spectra of five kinds of edible oils, olive oil, canola oil, soya bean oil, sun flower oil, peanut oil were obtained by one set of experiments, and the absorption peak spectra of different brands of canola oil were obtained by another set of experiments. After the normalization of the above two groups of experimental results, it is obvious that the general trend of their absorption peaks is very similar. Finally, the bandgap at transparency 0.5 was used to compare each edible oil in detail to determine the differences between the edible oils. The experimental results of this thesis validate the feasibility of using mid-infrared spectroscopy to test edible oil, and are promising to be extended to other food samples for food inspection. Master of Science (Electronics) 2022-05-13T02:16:59Z 2022-05-13T02:16:59Z 2022 Thesis-Master by Coursework He, Y. (2022). Food inspection using high performance quantum cascade laser. Master's thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/157730 https://hdl.handle.net/10356/157730 en application/pdf Nanyang Technological University
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
spellingShingle Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
He, Yuzhi
Food inspection using high performance quantum cascade laser
description Food inspection techniques are essential to address food safety issues. In this paper, based on a more systematic review of commonly used food inspection techniques, a special study on edible oil safety testing techniques is conducted. Through an extensive review of the literature, the author concluded that the late start of mid-infrared spectroscopy has strong advantages for food safety testing. According to the actual situation, edible oil is used as the experimental samples in this dissertation. The experimental equipment includes FTIR (Fourier Transform infrared spectroscopy), QCL (Quantum Cascade Laser), DAQ (Data Acquisition) and Lock-in amplifier. FTIR measures the complete spectrum of edible oil; QCL measures the characteristic absorption peaks in part of the spectrum of edible oil; DAQ can be used to acquire data. The Lock-in amplifier can extract weak signals from the noise and measure them accurately. The purpose of the experiments was to measure the spectra of different edible oils and then compare their absorption peaks as well as bandgap to determine their difference. In the experiment, the author first measured the olive oil and sun flower oil using FTIR, and selected the absorption peak (960-1300cm-1) from the spectrogram that is suitable for further measurement using QCL.The QCL experiment part includes two steps, one is to obtain the appropriate oil film thickness to ensure the spectrogram effect, and the other is to obtain the absorption peaks of various edible oils as well as bandgap for comparative analysis to determine the differences of the oils. The authors believe that the appropriate oil film thickness is very important for the measurement to obtain the spectrogram of the ideal absorption peak. If the oil film is too thick, the laser penetration is not enough to pass through; if the oil film is too thin, the spectrogram will show interference phenomenon, so the first step is to obtain the appropriate oil film thickness by adding spacer. After determining the film thickness, the absorption peak spectra of five kinds of edible oils, olive oil, canola oil, soya bean oil, sun flower oil, peanut oil were obtained by one set of experiments, and the absorption peak spectra of different brands of canola oil were obtained by another set of experiments. After the normalization of the above two groups of experimental results, it is obvious that the general trend of their absorption peaks is very similar. Finally, the bandgap at transparency 0.5 was used to compare each edible oil in detail to determine the differences between the edible oils. The experimental results of this thesis validate the feasibility of using mid-infrared spectroscopy to test edible oil, and are promising to be extended to other food samples for food inspection.
author2 Wang Qijie
author_facet Wang Qijie
He, Yuzhi
format Thesis-Master by Coursework
author He, Yuzhi
author_sort He, Yuzhi
title Food inspection using high performance quantum cascade laser
title_short Food inspection using high performance quantum cascade laser
title_full Food inspection using high performance quantum cascade laser
title_fullStr Food inspection using high performance quantum cascade laser
title_full_unstemmed Food inspection using high performance quantum cascade laser
title_sort food inspection using high performance quantum cascade laser
publisher Nanyang Technological University
publishDate 2022
url https://hdl.handle.net/10356/157730
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