Near Infrared Multispectral Detection of Talc Content in Flour
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
In order to detect excessive talc powder illegally added in flour, a near infrared multi-spectral quantitative detection method was proposed. Firstly, the samples with 0%, 0.5%, 1%, 3%, 5%, 10%, 15% and 20% talc powder mass fraction were prepared. The original spectra of the samples within the wavelength range of 900~1700 nm was acquired. With the increase of talc powder mass fraction, the amplitude of the sample spectrum curve decreased gradually in the range of 1160~1700 nm, and small absorption peaks appeared at 1393 nm in the spectrum curve of the samples with sufficient doping talc powder as compared with that of pure talc powder. By comparing the prediction results of the full-wavelength model corresponding to seven different pretreatment methods, the standard normal variables were selected as the optimal pretreatment method. Furthermore, three variable optimization methods were used to extract the optimal wavelengths and then the corresponding multispectral quantitative detection models for talc content in flour were established. The results showed that the competitive adaptive re-weighted sampling (CARS) method had the best detection effect among the three multispectral models. The verification set R2p was 0.998 and RMSEP was 0.282%. The continuous projection algorithm (SPA) method had the least number of wavelengths and the smallest collinearity among them. The detection limits of the three multi-spectral models corresponding to the three wavelength selection methods can all reach 0.5%, which can provide a theoretical basis for the development of portable or on-line testing instruments.
