Development of system on data acquisition and analysis of heat transfer and kinetics for Chinese cuisine

Abstract: The process characteristics of typical Chinese cuisine were analyzed into heat transfer, mass transfer, relative motion, and quality changes of fluid-particulate system in an open container, which showed that a temperature change of the heat transfer process played a crucial role in food quality. The current research object is to study the relationship between heat transfer and food quality of a fluid-particulate system by kinetics that is the bond of them. Based on aforementioned analysis, the primary purpose of cuisine is to make food materials mature and control heating which is the key to minimize food quality degradation while materials of cuisine are heated until done. In order to exactly express the degree of maturing in variations of temperature, Chinese cuisine maturity theory puts forward the novel kinetics functions in which maturity value (M value) and overheated value (O value) quantitatively expresses the degree of maturing and quality deterioration of foods respectively. Each of them was physically defined based on the equivalent heating time to reference temperature for respective quality factors. Validation and analysis of Chinese cuisine maturity theory, experiments of heat transfer and kinetics research on cuisine, and numerical simulation of the cuisine process all require basic test equipments to acquire data of heat transfer and kinetics of experiment. The existing instruments for validation of thermal process don't meet the requirements of the research of Chinese cuisine.Consequently, a system of data acquisition and analysis of heat transfer and kinetics for Chinese cuisine which automatically acquires temperature data in the process of heat transfer by multi-channels temperature acquisition module and simultaneously displays time-temperature profile, M value and O value of the integral computation of Simpson method that was programmed by Visual Basic software on the computer was developed.In the process of typical Chinese cuisine such as stir-frying, mixtures of fluid-particulate system are heated intensively in an extremely short time, and their temperatures change rapidly in a great range. Therefore, it is necessary that the temperature sensors of the system have high sensitivity and short response time. Eventually, superfine armored thermocouples with high precision and good stabilization were taken as the temperature sensors that verified that the measurement accuracy of temperature reached to ±0.05℃ and the response time was within 0.029 s. The numerical integration method affects the accuracy of the M/O value. The Simpson's integration method can meet the requirements of the accuracy of M/O value acquisition when the sampling interval is less than 1 sec. The system was applied to practical Chinese cuisine for the research on kinetics data of heat transfer and food qualities changes, which the sampling interval and kinetic parameters ZM/ZO were set at 0.5 s, 10 and 20℃ respectively, the errors of the Simpson method that was used in numerical integration of kinetics functions were ±1.16% (M value) and±0.58% (O value). All of the data of the acquisition and integral operation could be displayed on screen in real time, intelligently recorded, and saved on the computer. The result of the acquisition and numerical integration data proved that the system was applicable to data acquisition and analysis of the heat transfer and kinetics for Chinese cuisine. Further on, it could be used for validation and analysis of the theory of maturity value, applied to numerical simulation of the process of cooking and research on the principal Chinese cuisine techniques until it finds the optimization points for the heat transfer and kinetics of Chinese cuisine.