Tea Classification And Quality Evaluation Using Fluorescence Spectroscopy Based On Multi-wavelength LEDs

Tea, as a beverage next to the water, is popular with the people in the word. However, the quality of tea can have so large difference that customer cannot discriminate the different types of tea. While laser-induced fluorescence (LIF) technique can have an excellent application in tea classification and quality assessment depending on its characteristic of non-contact and low sample loss. But LIF technique cannot be spread because of the large system, high cost and big difficulty of discriminating similar tea samples. Therefore, LED-induced fluorescence based on multi-wavelength technique is proposed to improve the problem of discriminating similar tea samples, reduce the system cost and volume. Meanwhile, principle components analysis (PCA) is used to extract the important information from the collected data, reduce the dimension of the collected data and drop the difficulty of data processing.In this paper, the importance of tea and the problem in tea market is introduced firstly, and then the techniques applied in tea are analyzed detailed. So LED-induced fluorescence based on multi-wavelength technique is proposed to classify and assess tea. Secondly, the principle used in LED-induced fluorescence based on multi-wavelength technique and PCA are discussed, respectively. At last, each part of LED-induced fluorescence based on multi-wavelength system is introduced and the application of LED-induced fluorescence based on multi-wavelength system used in tea classification and quality assessment is demonstrated in accuracy and reliability.