Detection of pesticide residues on persimmon surface by hyperspectral imaging

The taste of persimmon is soft and juicy, which melts in the mouth and gives a sweet treat. Its unique taste often has a light fruity aroma, which is not too sweet, but can satisfy people's desire for sweets. Rich in A variety of nutrients, such as vitamin A, vitamin C, potassium, dietary fiber, etc. These ingredients have a positive impact on maintaining good health, enhancing immunity, and promoting digestion. During the growth of persimmon trees, farmers may use pesticides to control diseases and pests to ensure the yield and quality of persimmon trees. Improper or excessive use of pesticides may lead to pesticide residues on the surface of persimmon.

1. Technical principles

Hyperspectral imaging technology combines imaging technology and spectral technology to obtain continuous and narrow band image data with high spectral resolution by detecting two-dimensional geometric space and one-dimensional spectral information of the target. This technique can simultaneously process the image information and spectral information of the sample, and realize non-destructive, fast and real-time multi-parameter measurement.

2. Experimental materials and methods

2.1 Persimmon samples of similar color, consistent size and good maturity were selected for the experiment, and cleaned and dried.

2.2 Pesticide types Select specific pesticide types, such as chlorpyrifos, pyrimethamine, etc., for spraying on persimmon samples.

2.3 Pesticide Spraying and sample grouping The persimmon samples were randomly divided into different groups, each group was sprayed with different kinds of pesticides, and a control group was set (only distilled water was sprayed).

2.4 Setting Data Collection Parameters

Before collecting hyperspectral images, parameters such as object distance and exposure time need to be set to ensure that the acquired images are clear and accurate. For example, the object distance is set to 45cm and the exposure time is set to 0.05s.

3. Hyperspectral data acquisition and processing

3.1 Data Collection

The images of persimmon samples sprayed with different pesticides were collected by hyperspectral imaging system. In the process of acquisition, it is necessary to keep the height of the lens unchanged and complete the image acquisition by pushing and sweeping through the movement of the electro-migration platform.

3.2 Data Processing

The collected hyperspectral images were preprocessed, such as denoising, waveform fitting and spectrum matching, to extract the spectral features of persimmon surface. Then, the spectral characteristics were compared with the known pesticide spectrum library to identify the pesticide residues on the surface of persimmon.

4. Results and analysis

According to the comparison results, the types and concentrations of pesticide residues on persimmon surface were analyzed. Compared with traditional pesticide residue detection methods, the detection method based on hyperspectral imaging technology has the advantages of non-destructive, rapid, real-time, multi-parameter simultaneous measurement, etc., and can better meet the needs of modern agricultural product quality and safety detection.

5. Conclusion and prospect

The detection of pesticide residues on persimmon surface based on hyperspectral imaging technology has a broad application prospect. With the progress of technology and the reduction of cost, this technology is expected to be more widely used in the field of fruit and vegetable quality and safety detection. In the future, the technology will develop in the direction of higher resolution, faster detection speed, and lower cost, providing more powerful technical support for agricultural product quality control and food safety testing.