Method for detecting Escherichia coli in milk based on ultraviolet-visible spectrum technology

Abstract

The invention provides a method for detecting Escherichia coli in milk based on an ultraviolet-visible spectrum technology. Under the complex background environment similar to that of the milk, the problems that detection spectra of microorganisms are affected by unfavorable factors, the phenomena of characteristic wavelength red shift, obvious noise and the like are generated, consequently spectral characteristics are difficult to pick up, and the accuracy of quantitative detection results is low can be effectively solved. The method comprises the steps that firstly, Escherichia coli powder is activated and subcultured, and a to-be-detected bacterium suspension is prepared; an ultraviolet spectrophotometer obtains ultraviolet-visible spectra of the to-be-detected bacterium suspension at different culture times; noise interference is eliminated through a standard normal correction method and an S-G convolution smoothing method; the spectral characteristic red shift phenomenon is explained from the angle of a formation mechanism of a benzene ring conjugated structure, and thus the characteristic waveband range is determined; the characteristic wavelengths are picked up in the characteristic waveband through a continuous projection algorithm, and the characteristic wavelengths are effectively screened according to the secondary growth law of the microorganisms; and the model relationship between the characteristic wavelengths and the total number of the microorganisms is established through a partial least squares method, and the total number of the Escherichia coli in the milk is quantitatively analyzed

Description

technical field [0001] The invention relates to an ultraviolet-visible spectrum detection technology, in particular to a detection method for the total number of Escherichia coli in milk. Background technique [0002] Escherichia coli is the foodborne pathogen with the highest detection rate in milk, and it is an internationally recognized indicator bacterium for hygiene monitoring. Therefore, it is important to capture the specificity of Escherichia coli more sensitively and realize its efficient and rapid detection to ensure the safety of dairy products in my country. significance. At present, the detection and counting of Escherichia coli in milk mainly rely on conventional bacteriological culture methods: multi-tube fermentation method and plate counting method, but these methods are time-consuming and laborious, the operation is highly professional, and cannot meet the needs of rapid and non-destructive detection . [0003] UV-Vis absorption spectroscopy is often used ...

AI Technical Summary

Problems solved by technology

[0004] The main reason is that milk contains complex components, and the uneven particle size distribution of biological macromolecular particles such as protein and fat in milk will cause noise interference caused by factors such as light scattering, and the detection spectrum of Escherichia coli will also bring characteristic spectra. Influences such as red shift, difficulty in picking up characteristic wavelengths, and inaccurate quantitative detection results

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