Study On Nondestructive Measurement Multiple Pesticide Residues On Mandarine Surface Based On Near-Infrared Spectroscopy

In recent years, the quality of food safety problem has already become the focus of the whole society, this is mainly because people’s life style has changed from the type of enough food structure to healthy food structure. The great change of the people’s dietary structure requires higher standards of food quality. Two important kind of mandarine, LuGan mandarine and NanFeng mandarin both are famous for their unique features, and production and exports increased year after year, it has great significance to nondestructive measurement multiple pesticide residues on mandarine surface.Firstly, A near infrared pesticide residue detection platform is established based on the near infrared spectrum technique, YongChun LuGan,one kind of the mandarines as the research object, sprayed with different concentration of the mixture of acephate and chlorpyrifos pesticide on surface were studied. The ratio of1:1mixture of two pesticides was diluted to1:100,1:300and1:500solution with running water.192LuGan mandarines were sprayed by solutions. The spectra of LuGan samples were collected with a wavelength range of350～1800nm.The pesticide residues on LuGan mandarine surface were determined by gas chromatography with NY/T761-2008method. Two different spectral pretreatment methods of standard orthogonal variable transformation(SNV) and multiplicative scatter correction(MSC) were used for establishing the prediction models of synergy interval partial least square (SiPLS) and PCR,which was determined the pesticide residue on LuGan mandarine surface. Comparing the results of model, it shows that, the acephate model was established by SiPLS after MSC pretreatment achieved the optimal performance. The correlation coefficient (R)of the optimal model of prediction set were0.8199,and the chlorpyrifos model was established by SiPLS after SNV pretreatment achieved the optimal performance. The correlation coefficient(R) of the optimal model of prediction set were0.8434.Secondly, NanFeng mandarine,another kind of the mandarines as the research object, sprayed with different concentration of the mixture of acephate and chlorpyrifos pesticide on surface were studied. The ratio of1:1mixture of two pesticides was diluted to1:500,1:600and1:700solution with running water, NanFeng mandarines were sprayed by solutions. The spectra of NanFeng mandarins samples were collected with a wavelength range of350～1800nm.The pesticide residues on NanFeng mandarine surface were determined by gas chromatography. Two different spectral pretreatment methods of standard orthogonal variable transformation(SNV) and multiplicative scatter correction(MSC) were used for establishing the prediction models of synergy interval partial least square (SiPLS) and Multiple Linear Regression(MLR),which was determined the pesticide residue on NanFeng mandarine surface. The research indicates that the detection of pesticides residues acephate on the NanFeng mandarins acephate model was established by SiPLS after SNV pretreatment achieved the optimal performance. The correlation coefficient (R)of the optimal model of prediction set were0.7388, and the chlorpyrifos model was established by MLR after MSC pretreatment achieved the optimal performance. The correlation coefficient (R) of the optimal model of prediction set were0.807.PLS, PCR and MLR data analysis methods were used In this study, large number of Near-Infrared spectral data were reduced, not only greatly increases the speed of operation, but also simplifies the complexity of the prediction model. Although two pesticides prediction accuracy of the models are not very high, but compared to the traditional technologies, There are advantages of rapid、nondestructive of Near-Infrared spectroscopy technology, and precision will be improved through the follow-up study further.The research indicates that the detection of nondestructive measurement multiple pesticide residues on mandarine surface based on Near-Infrared spectroscopy providing some theoretical basis for future non-destructive measurement pesticide residues on mandarine surface.