Development Of Near-infrared Spectroscopy Analysis System And The Application Research On Food Safety

Nowadays, people’s living standard has been greatly improved with China’s rapid economic development. People have paid more attention to nutrition, health and food safety. In recent years, incidents of food hygiene and safety such as melamine, drainage oil, plasticizers and poisonous milk powder emerge in an endless stream. Food safety problem has attracted the concern of the whole society. Food safety inspection technology has become a hot research and application topic in society widely.Near-infrared spectroscopy(NIRS) analysis technique which is a new type of food safety detection has many advantages.it is rapid, low cost, non-destructive measurement and so on. Combined with chemometrics and computer technology, on-site inspection for food ingredients can be achieved. According to the different ways of light splitting, there are several kinds of near-infrared spectroscopy analysis instruments. Acousto-optic tunable filters(AOTFs) is new module of light splitting, it has stable spectral characteristics. The control of spectrum can be flexible, fast, and without movement. This paper provided an overview of near-infrared spectral analysis technology and the related research progress. A brief introduction to the working principle and application characteristic of AOTF device was proposed. Then the design of near-infrared spectroscopy analysis system based on AOTF is introduced. The analysis system prototype performance test was completed. The exploratory application tests of food safety detection are carried out by using the system. Qualitative and quantitative testing of the major components of the milk samples was carried out via typical analysis methods and a mathematical model of NIRS.Based on the optical principle of AOTF, The output signal of the detector was modulated by the RF signal which modulated by the square wave. Then the lock-in amplifier demodulation technology was used to extract the target signal. This method can effectively improve the signal-to-noise ratio of the system. The design of dual detector with double optical path could compensate light source stability and optical interference caused by light reflection in the optical path. The performance test of the prototype system and the application test results indicated well viability and reliability of the design of near-infrared spectroscopy analysis system. It can be used to collect and analyze the transmission spectrum of liquid samples.Thus, this study provides a technical reference for the development of spectroscopy instruments and their applied research.