2 research outputs found
Lab-Made Electronic Nose for Fast Detection of Listeria monocytogenes and Bacillus cereus
No full textThe aim of this study is to determine the performance of a lab-made electronic nose (e-nose) composed of an array of metal oxide semiconductor (MOS) gas sensors in the detection and differentiation of Listeria monocytogenes (L. monocytogenes) and Bacillus cereus (B. cereus) incubated in trypticsoy broth (TSB) media. Conventionally, the detection of L. monocytogenes and B. cereus is often performed by enzyme link immunosorbent assay (ELISA) and polymerase chain reaction (PCR). These techniques require trained operators and expert, expensive reagents and specific containment. In this study, three types of samples, namely, TSB media, L. monocytogenes (serotype 4b American Type Culture Collection (ATCC) 13792), and B. cereus (ATCC) 10876, were used for this experiment. Prior to measurement using the e-nose, each bacterium was inoculated in TSB at 1 × 103–104 CFU/mL, followed by incubation for 48 h. To evaluate the performance of the e-nose, the measured data were then analyzed with chemometric models, namely linear and quadratic discriminant analysis (LDA and QDA), and support vector machine (SVM). As a result, the e-nose coupled with SVM showeda high accuracy of 98% in discriminating between TSB media and L. monocytogenes, and between TSB media and B. cereus. It could be concluded that the lab-made e-nose is able to detect rapidly the presence of bacteria L. monocytogenes and B. cereus on TSB media. For the future, it could be used to identify the presence of L. monocytogenes or B. cereus contamination in the routine and fast assessment of food products in animal quarantine
Rapid Detection of Escherchia coli and Salmonella Typhimurium Using Lab-Made Electronic Nose Coupled with Chemometric Tools
Get PDFThis study aims to investigate the performance of a lab-made electronic nose coupled with chemometric tools for detecting Escherichia coli (E. coli) and Salmonella Typhimurium (S. Typhimurium) inoculated in media. The pathogenic E. coli and S. Typhimurium play a significant role as the agent causing food-borne diseases, posing a threat to human health worldwide. Some advanced analytical instruments like RT-PCR and GC-MS are often used for detecting such pathogenic bacteria. Unfortunately, they are not suitable for rapid and routine measurements because of time-consuming, require experts, and complicated sample preparation. Otherwise, electronic nose (e-nose) has been reported to be successful for profiling volatile compounds released by various biological materials. The e-nose comprised eight types of metal oxide gas sensors connected with a data acquisition system and chemometric tools. For this purpose, Fast Fourier Transform (FFT) was applied for signal pre-processing and feature extraction to all datasets collected by the sensor array in the e-nose. Furthermore, chemometric tools are used for classification models of all extracted features, including linear and quadratic discriminant analysis (LDA and QDA) and support vector machine (SVM). As a result, SVM showed the highest performance, enabling identifying E. coli and S. Typhimurium inoculated TSB with an accuracy of 99% and 98%, respectively. Among the chemometric tools, the e-nose-SVM also resulted in the highest accuracy in differentiating E. coli from S. Typhimurium of 84%. These results motivated e-nose to have a high prospect to rapidly detect such bacteria for food safety and quality control inspection, particularly potential quarantine products
