| Nowadays, with the continuous development of the national economy and rising living standards, people are asking for high-quality fruits. A portable non-destruction instrument for measuring the soluble solids content of apple is developed. It contributes a lot to the commercialization of apples because this device can gain the apple sugar content accurately and quickly. Meanwhile, its compact and portable design makes the site monitoring become a reality. It helps for scientific management, best storage, classification by quality during sale and etc. In other words, it appears a broad application prospect and market prospects.In this paper, research on Fuji apples from YanTai, ShanDong province, focus on apple measurement for sugar content and designed non-destruction apple sugar content detector invents the non-destructive device. What's the innovation of this design is the integration integrated optical spectrum instrument with sending-receiving component. It means much smaller in size, lighter in weights and lower in cost compared with abroad products of the same kind which are expensive and bad after-sale service. Meanwhile, it makes up for domestic vacancy situation and brings orchard workers and fruiterers with much higher cost-performance practical devices. It's more convenient, easier and more efficient for users since embedded operation system is chosen.Substantial achievements have been made based on the hardware platform, combined visible or near infrared spectral with Chemometrics analysis technology.The main research work and conclusions can be summarized as below:1. After looking up concerning literature, comparing the advantages and weakness between several common spectroscopic detection methods, a spectra acquisition mode is designed according to diffuse transmission.2. According to the theory and the overall design scheme of the Near Infrared Spectroscopy Detection Technology, the apple sugar content nondestructive detection instrument is built, which is composed of light path, data processing and accessory module.In the light path design, specification of halogen lamps is confirmed after comparing several different brands and combining with spectral range, strength and stability. As to light source arrangement, the light path based on diffuse transmission, conducting with fiber is established and a component used for sending and receiving light is designed. Well, the data processing module is a board integrated with core Cortex-A9.3. Complete and peeled apples are selected for detection to reduce the affection of detection accuracy. It is concluded that curves of transmission spectra don't change whether apples with peel or not after analyzing curves of different parts but has some influence on the magnitude of the transmittance curve.4. The spectrometer(analysis wavelength 400-1000nm) self-developed is put into service to collect optical transceiver diffuse transmission spectral curves. In addition, the full spectrum of the sample is researched and explored in average and smooth pretreatment ways.Curves are divided into zones according to wavelength, and then PLS model is established to predict the sugar content of apple. By comparison, the full spectrum of PLS models set up in average and smooth pretreatment way are better than that of divided by wavelength zones.The PLS models perform well with correcting correlation indexcR =0.96,RMSEC=0.31, predicted correlation indexpR =0.93 and RMSEP=0.34. |
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