Research On The Application Of Near Infrared Spectroscopy In Food Inspection And Biological Analysis

Near infrared spectroscopy(NIR) owns the characters of quickly, nondestructive, and can be applied for simultaneous quality evaluation and quantitative analysis of chemical components in complex samples. This technique has been widely used in the fields of petrochemicals, organic synthesis, analytical chemistry, environmental chemistry, clinical medicine, etc.. In this thesis, three detected models had been established and been applied in food safety detection and rapid clinical examination. The thesis includes four chapters.In the first chapter, the conception and characteristics of the near-infrared spectroscopy technique and the procedure about the application of NIR were described. In addition, the data analysis methods in chemometrics and the application of NIR in the fields of food and medicine analysis were introduced also. At last, the purpose and contents of this research had been pointed out.In the second chapter, NIR technique had been applied to detect the plasticizers in the edible essence from food industry. The principal component analysis (PCA) method was used to identify whether the samples contained DEHP and DINP A quantitative analysis model by using partial least squares (PLS) had been established to detect the contents of DEHP and DINP with the concentration range of 0～100 mg/kg. The relative errors of the prediction results for DEHP and DINP are-1.23 %～3% and-1%～3.6%, respectively, and the relative root-mean-square error of prediction (RMSEP) are 1.39 and 0.98, respectively. A quantitative analysis model for detection of DEHP in in food packaging materials had been developed also. It is found the relative errors of the prediction results are-0.27～0.016 and the RMSEP is 0.12, which indicates the established model has good stability and robustness.In chapter three, a quantitative analysis model for ganoderma lucidum spore oil authentication was established. The sunflower oil, barley oil, peanut oil, corn oil and blend oil are mixed into the ganoderma lucidum spore oil respectively with the volume percentages from 0 to 100. Then the optimal spectral bands are selected and a quantitative analysis model was established by using PLS. The model has a relative prediction error in the range from-0.357 to 0.435 for the mixed oil with different adulterated percentages.In chapter four, the NIR technique was applied to identify and quantitative analysis three clinical bacteria, i.e Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), and Staphylococcus aureus (ATCC 29213). Results suggest that NIR spectroscopy can distinguish these three bacteria with high accurately. PLS was applied to establish the quantitative analysis model for each bacteria. And then these models were successfully used to determine the bacterial amount for these three species of bacteria in solution in the range of 2-8 log CFU/mL. Researches show that three quantitative analysis models have a relative prediction error in the range from-1.113 to 1.617, and the RMSEPs are 0.49,1.08, 0.77. This rapid detection method can be used in clinical examination.