Studv On Multi-wavelength LED-induced Fluorescence Spectroscopy Technology In Food Detection

In recent years, food safety has attracted more and more attentions but there are not perfect quality testing standards for some food on the market. Against the status quo, in this paper, a simple, compact, low cost nondestructive testing technology based on multi-wavelength LED-induced fluorescence spectroscopy is proposed for testing the quality of food. Firstly, a detecting system based on multi-wavelength LED-induced fluorescence spectroscopy is designed in this paper, and using this system, fluorescence spectrum of the sample can be collected. Then, fluorescence spectra filtering out the background signal and normalized at the maximum of spectrum are used for subsequent data processing. In the end, the principal components are extracted using Principal Component Analysis (PCA) or Partial Least Squares (PLS), and the regression model is established using the selected principal component for evaluating or forecasting the sample quality.In order to verify the accuracy of the system designed in this paper and the data processing methods, the quality of tea, coffee and tobacco is studied, respectively. Different kinds of tea leaves and tea beverages are discriminated, and different grades of Xihu Longjing are distinguished. Different types of coffee and instant coffee quantitative measurement are studied. The classification of four kinds of tobacco is made, and hybrid wavelength detection method is proposed. The results of experiments show good application prospect of the multi-wavelength LED fluorescent spectroscopy in food testing.