Rapid Identification of Tiegun Yam by Near Infrared Spectroscopy Combined with Conformity Test

In today´s society, it´s a phenomenon that many other varieties of yam are pretended to be tiegun yam in the market. In this paper, Near infrared(NIR) spectroscopy combined with conformity test was used to establish a method which can quickly discriminate tie gun yam from other varieties. Firstly, the NIR spectra of 200 samples of yam, including 45 tie gun yam and 155 non-tie gun yam, were acquired by OPUS/IDEN software. The spectra in 8686.4-6788.7cm^-1 and 5430.9-4181.2cm^-1 was used to establish the discrimination model after being processed by First Derivative and Vector Normalization. The conformity index(CI) of 180 samples were calculated to establish the conformity test model and the other 20 samples were used to validate the model. The result shows that when the CI value was limited to be 3.5, all spectra of the tie gun yam and non-tie gun yam were well identified. According to the validation, all the other 20 samples were in accord with actual results. It can be concluded that NIR spectroscopy technique was an accurate and effective approach to identify tiegun yam and non-tiegun yam combining with conformity test.