Soybean sorting based on protein content using X-ray fluorescence spectrometry

The purpose of this research was to evaluate performance of an energy-dispersive X-ray fluorescence (XRF) sensor to classify soybean based on protein content. The hypothesis was that sulfur signals and other XRF spectral features can be used as proxies to infer soybean protein content. Sample preparation and equipment settings to optimize detection of S and other specific emission lines were tested for this application. A logistic regression model for classifying soybean as high- or low-protein was developed based on XRF spectra and protein contents. Additionally, the model was validated with an independent set of samples. Global accuracies of the method were 0.83 (training set) and 0.81 (test set) and the corresponding kappa indices were 0.66 and 0.61, respectively. These numbers indicated satisfactory performance of the sensor, suggesting that XRF spectral features can be applied for screening protein content in soybean.

Automated summary

The purpose of this research was to evaluate the performance of an energy-dispersive X-ray fluorescence (XRF) sensor for classifying soybean based on protein content. It was found that sulfur signals and other XRF spectral features can be used as proxies to infer soybean protein content. A logistic regression model was developed based on XRF spectra and protein contents, achieving global accuracies of 0.83 (training set) and 0.81 (test set). These results indicate that XRF spectral features can be applied for screening protein content in soybean.