Application Of Near Infrared Spectroscopy Analysis Technique In Growing Message Acquisition Of Pointed Paprikas Sample Leaves

Since Near Infrared Spectroscopy analysis technique has many advantages, such as simpleness, rapidity, high accuracy, no pollution, good repeatability, and easy on line analysis, it has been widely applied in many fields of research and production, with rapid development process and good prospects. However, at present, the NIR analysis is mainly applied in petrochemical, grain and medical industries. To broaden the application area of NIR analysis and find a rapid and nondestructive method for plant growing message acquisition, pointed paprik was selected as the research object, and NIR analysis technique was used to obtain messages of some chemical components in pointed paprik sample leaves, which are related to their growing status. There were two research focuses in the study. First, the influence of different approaches for pre-treatment, model construction, phase selection, and abnormal sample removal during applying NIR technique to obtain the spectrum information of chlorophyll in pointed paprikas sample leaves on the predictive models was analyzed. Then, the predictive models were constructed by using the spectrum information obtained with NIR technique, with the help of teniques of spectrum analysis and chemical measurement.In this study, moisture contents and chlorophyll in pointed paprikas sample leaves were obtained by standard chemical analysis techniques. Diffuse reflection spectra were obtained by using NEXUS spectrometer (Nicolet Co, USA), and acquisition and analysis methods. Study on experiment techniques for NIR spectrum analysis was emphasized in the research. Based on the analysis of sample treatment, scan condition, spectra preprocessing, modeling method, and abnormal sample elimination method, the following results were obtained.For water content, the best modeling results were obtained by using original spectra +MCS based on optic fiber accessory. The parameters are as follows:R=0.95978, RMSEC=0.00735, RMSEP= 0.0165, f=8For chlorophyll content, the best modeling results were obtained by using preprocessed spectra (first-order derivative+13points smoothing+SNV) based on optic fiber accessory. The parameters are as follows:R= 0.95208, RMSEC= 0.0775, RMSEP= 0.117, f=8 For SPAD, the best modeling results were obtained by using preprocessed spectra (first-order derivative+5 points smoothing+MSC) based on optic fiber accessory.The parameters are as follows:R= 0.99273, RMSEC= 6.32, RMSEP=1.21, f=8The partial least squares (PLS) was shown as the best modeling methods. The modeling results indicated that the NIR technique was accurate enough to replace standard chemical analysis methods for rapid detection of water content and chlorophyll content values of pointed paprikas sample leaves.