Method for detection of milk mixed with urea based on synchronous-asynchronous two-dimensional near-infrared correlation spectroscopy

Abstract

The invention relates to a method for detecting urea-doped milk based on synchronous-asynchronous two-dimensional near-infrared related spectra. The method comprises the following steps: 1, preparing pure milk for experiments and urea-doped milk; 2, respectively scanning the near-infrared spectra of the pure milk for experiments and the urea-doped milk; 3, calculating to obtain the normalization synchronous-asynchronous two-dimensional near-infrared related spectrum matrix of the pure milk for experiments and the normalization synchronous-asynchronous two-dimensional near-infrared related spectrum matrix of the urea-doped milk; 4, building a discrimination model with a categorical variable matrix by a multi-dimensional partial least squares; 5, scanning and calculating unknown sample milk to obtain the synchronous-asynchronous two-dimensional near-infrared related spectrum matrix of the unknown sample milk, and substituting into the discrimination model to obtain whether urea is doped or not. Similarity and difference information of a to-be-analyzed system, changing with external interference, are fully utilized, and the influence of the single adoption of synchronous spectrum or asynchronous spectrum matrix redundant information on the model is overcome. The method is simple and scientific, and the analysis efficiency and the discriminating accuracy are high.

Description

technical field [0001] The invention belongs to the field of detection methods, in particular to a method for detecting milk mixed with urea based on a synchronous-asynchronous two-dimensional near-infrared correlation spectrum. Background technique [0002] Milk is a nutritious food that contains essential elements for human life, so it is popular with most consumers. However, due to the scattered sources of milk in China and the complexity of milk testing, some unscrupulous traders often add some "foreign substances" that do not belong to milk, such as urea and melamine, to dairy products. These "foreign substances" can turn unqualified milk into qualified milk, allowing it to gain more profits. These adulterated milk have seriously damaged the interests of dairy companies and consumers. [0003] Conventional one-dimensional spectroscopy has been widely used to identify adulterated foods, such as milk, milk powder, honey, apple juice, and olive oil. However, milk is a c...

AI Technical Summary

Problems solved by technology

However, since the synchronous two-dimensional correlation spectrum is symmetric about the main diagonal, there is a problem of redundancy in the modeling information, and the matrix only reflects the "similarity" information of the system to be analyzed with the external disturbance, and lacks the "similarity" with the external disturbance. The characteristic information of "difference" changes

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