Time-Resolved Laser-Induced Breakdown Spectroscopy for Accurate Qualitative and Quantitative Analysis of Brown Rice Flour Adulteration

Abstract

To solve the adulteration problem of brown rice flour in the commodity market, a novel, accurate, and stable detection method based on time-resolved laser-induced breakdown spectroscopy (TR-LIBS) is proposed. Qualitative and quantitative analysis was used to detect five adulterants and seven different adulterant ratios in brown rice flour. Being able to excavate more information from plasma by obtaining time-resolved spectra, TR-LIBS has a stronger performance, which has been further verified by experiments. For the qualitative analysis of adulterants, the traditional machine learning models based on TR-LIBS, linear discriminant analysis (LDA), naïve Bayes (NB) and support vector machine (SVM) have significantly better classification accuracy than those based on traditional LIBS, increasing by 3–11%. The deep learning classification model based on TR-LIBS also achieved the same results, with an accuracy increase of more than 8%. For the quantitative analysis of the adulteration ratio, compared with traditional LIBS, the quantitative model based on TR-LIBS reduces the limit of detection (LOD) of five adulterants from about 8–51% to 4–19%, which effectively improves the quantitative detection performance. Moreover, t-SNE visualization proved that there were more obvious boundaries between different types of samples based on TR-LIBS. These results demonstrate the great prospect of TR-LIBS in the identification of brown rice flour adulteration.

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…There has been continued interest in utilising LIBS for species identification and authenticity of food products . Ma and co-workers 134 presented a new approach for LIBS data collection for the identification of adulterants in brown rice flour. The researchers termed this approach ‘time resolved’ LIBS, where spectra were collected from multiple gate delay times and spliced together to increase the amount of data per sample.…”

Special Issue “Advanced Spectroscopy Techniques in Food Analysis: Qualitative and Quantitative Chemometric Approaches”

“…Additionally, the effect of moisture content on the analysis of quality attributes of red pepper powder is explored using a hyperspectral system, providing valuable insights into the impact of moisture on food analysis outcomes [10]. Moreover, time-resolved laserinduced breakdown spectroscopy is employed for the accurate qualitative and quantitative analysis of brown rice flour adulteration, offering a promising approach to combat food fraud and adulteration [11].…”