The Research On The Method Of Water Injection Meat Testing Based On Bioelectric Impedance Spectrum

Meat moisture is an important factor which affects the quality of meat.It is an important indicator that must be detected in the storage,acquisition,and processing.The behavior of water injection makes its moisture content exorbitant,causing bacteria breed intensified and rotten meat.However,dehydration can cause a direct economic loss,destr uction of organic matter,influence its colour and lustre.Every year in our country,due to the moisture content is too high caused tens of billions of tons of meat meat mildew deterioration in storage or transportation.The incomplete and inaccurate technology of Water injection meat detection,the theory limitations of Meat equivalent impedance single variable model organism and the subsequent information processing and the development and application of compensation method make it difficult to detect water injection meat rapidly and accurately.The traditional method of detecting water injection meat have the problems of the time of measuring and the impedance measurement accuracy.The main porpose of this thesis is to solve this problems.The first chapter is introduction,which summarizes the injection meat and its detection methods briefly,analysis water injection meat detection based on bioelectrical impedance spectrum at home and abroad and discuss the value and meaning of the research.The second chapter analyzes RC equivalent circuit model of biological tissue,Cole theorem and dispersion theory,then introduce the relationship between water content and water injection electrical impedance characteristics of meat.Biological tissue electrical impedance spectrum measuring principle and measuring method are introduced.In the third chapter,we briefly introduces the hardware implementation of bioelectrical impedance spectroscopy measurement system,including the overall design of the hardware and the design of each module,based on multiple frequency synchronous measurement technology of Multisine excitation signal source,voltage controlled current source(VCCS),four electrode measurement signal sampling,dual channel modulus conversion and dual channel based on Nios II control data caching and read,and the the design of the power supply module of impedance measurement system.In the fourth chapter.the thesis mainly introduces the software design of impedance spectroscopy measurement system and the concrete implementation.Firstly it introduces the main program design of the impedance spectroscopy measurement system,then respectively introduces the Multisine signal module,bioelectrical impedance signal acquisition module and low-speed peripherals modules,namely,human-computer interaction module,communication and print module software design.Then it introduces the impedance data collection process,and the whole cycle of single frequency sine signal and the whole cycle sampling comparing with the results of the study,based on this,through the experiment simulation demonstrates MFS technology synchronous measurement Multisine signals in the whole cycle can eliminate the phenomenon of frequency spectrum leakage and improve the measuring accuracy of impedance.The application of digital filter can eliminate the interference signal,least square method was applied to Cole arc fitting in order to acquire impedance model parameters.Finally,it aims to verify the results presented in this thesis which the accuracy of the test method of water injection meat based on bioelectrical impedance spectrum,taking advantage of ridge pig meat for the analysis of the experimental samples to validate the method.Experiments prove that the biological electrical impedance spectrum measurement system based on the method developed in this paper can detect water injection meat quickly and accurately.