Study On The Analysis And Detection Of Near-infrared Absorption Spectra Of Rice Seeds

As the one of the most important staple food in the world today,screening the quality of rice seeds can effectively improve rice yield.Because of the advantages of fast and non-destructive spectroscopy,near infrared spectroscopy(NIRS)has been widely used for qualitative and quantitative analysis of single grain seeds.Compared with traditional rice seed activity detection methods,which are time-consuming,heavy and not environmentally friendly,NIRS can more accurately obtain seeds with target traits,which is conducive to the real-time monitoring of seed quality analysis,acquisition and storage.It has become the trend of the development of agricultural quality monitoring to apply near-infrared spectral analysis technology to grain analysis.In this paper,the near infrared spectroscopy(NIRS)was used as a method to detect the viability of rice seeds.Because of the urgent need to detect the vigor grading of rice seeds with palea shell in seed selection and the existing problems of brown rice detection technology,this study designed a complete nondestructive grading detection system for rice seed activity based on near-infrared laser spectroscopy.A discriminant model for seed viability grading of rice was established by using the detection data of the system and combining with multivariate analysis.Nondestructive grading detection of rice seeds with different vigor levels was realized.Therefore,the main contents are as follows:(1)In this paper,a transmission measurement method was proposed to establish a near-infrared absorption spectrum detection system to test and analyze rice seeds with palea shells.The system mainly consists of a super continuous light source with high optical power and wide band,a grating spectrometer with high resolution and high stability,a pinhole aperture with limited light spot size of 1.5mm,a focusing system with a focal length of 10 mm and a spectral data receiving instrument,which can detect the transmission spectrum of rice seeds with palea layer.(2)The near-infrared absorption spectra of three rice seeds with palea shells of different years and varieties were measured,and the original spectra were processed by various preprocessing methods.The results show that the energy gradient of rice seeds is related to the characteristic absorption peak of the near infrared absorption spectrum,and the preprocessing algorithm combining normalization,second derivative correction and orthogonal signal correction has the best optimization effect on the seed spectrum.(3)The principal component analysis(PCA)model was established to reduce the dimension of the spectrum,and the optimal principal component number was determined.The results showed that the partial least squares model of rice seed activity analysis had better classification effect,and the accuracy of correction set and verification set were 94.44% and 95.92% respectively,and the germination rate of rice seed after screening was up to 97.17%.(4)The influence of the light source energy,the average frequency of the spectrum and the integration time on the accuracy of the model was analyzed experimentally,and the optimal detection parameters of the system were selected.The results show that the transmission absorption spectrum detection system designed in this paper,combined with the PLS-DA discriminant model,can classify rice seeds with different vigor,and the nondestructive classification of rice seed vigor based on the near-infrared spectrum information is feasible and has high prediction accuracy.