Development Of Portable Volt-ampere Agricultural Electronic Tongue System And Its Application In Quality Inspection Of Yellow Rice Wine

The taste quality is one of the main characteristics of liquid food,which is closely related to the composition and content of the food.The electronic tongue technology based on electrochemistry,with its cross-response,fast and efficient characteristics,is developing rapidly in this field.However,the current volt-ampere electronic tongue detection system often has a single function,difficult sample data storage,low degree of intelligent discrimination and poor practicability.Therefore,this paper developed a portable volt-ampere electronic tongue system,and developed a set of upper computer interaction software with complete functions based on QT4.8.2 the hardware module of the system can realize data acquisition,automatic sampling,constant temperature heating and the interactive software can realize the underlying communication,automatic data storage,result discrimination and other functions.Finally,the main functional modules of the system were tested and optimized,and it was applied to the detection of yellow rice wine category,wine age and sweetness,to verify the detection performance of the system.The main contents and conclusions of this paper are as follows:(1)The portable volt-ampere electronic tongue detection system includes: 5 main function modules.Among them,the 5 main function modules are: automatic sampling function module,thermostatic heating function module,bionic taste function module,lower computer function module and upper computer function module.The bionic taste function module is the core of voltampere electronic tongue detection system,which is composed of combined electrode,conversion and conditioning circuit and 16-bit AD7606 data acquisition module,which can effectively achieve the comprehensive acquisition of sample characteristic information.The upper computer is a human-computer interaction interface developed based on QT 4.8.2,including one main function interface and five sub-menu function interface.Data processing and result discrimination model are embedded in the upper computer software to enhance the automatic analysis ability of the system.The lower computer uses STM32F4 series MCU as the bottom control center.Between the upper computer and the lower computer through USB data line real-time information transmission.(2)In order to improve the working performance of the portable volt-ampere electronic tongue detection system,the performance tests and optimization of the bionic taste function module,the thermostatic heating function module were carried out.After the test and optimization of the bionic taste function module,the sampling signal amplitude is stable and the noise is small.The performance of the combined electrode is stable in long-term use.Within 20 days,the deviation of the characteristic values of Ag,Au,Pt and Rh working electrodes are all less than5%.In the range of 20℃～50℃,the temperature field uniformity of the module is less than 1℃,and the temperature deviation and fluctuation of each point are less than 0.5℃,which can provide a relatively stable testing environment for the sample.(3)In order to verify the detection performance of the portable volt-ampere electronic tongue detection system,test experiments were carried out on the category,wine age and sweetness of yellow rice wine.PCA and discrete wavelet algorithm were used in the system to effectively reduce the dimension of the original data,and KNN,BP and SVM algorithms were used to establish the discriminant model,which all obtained good discriminant effect,indicating that the system can be effectively used to detect the quality of yellow rice wine.In addition,it is found that the sample response signal is also affected by the bubbles on the electrode surface and the frequency and amplitude of the excitation pulse signal.Operators need to take the above factors into consideration to obtain the best detection effect.