Research On Ultrasonic-Assisted Immersion Chilling And Freezing Processof Silver Carp Meat

In recent years,the scale of China’s aquatic products import and export industry has shown a growth trend,but China is relatively backward in refrigeration technology,equipment and effectively maintaining the quality of low-temperature frozen food and refrigerated food is an urgent problem to be solved at this stage.So freezing preservation is very important in today’s era.Impregnation freezing is widely used in food freezing processing due to the advantages of fast freezing rate,low energy consumption,low dry consumption and high freezing quality.Promoting the freezing efficiency of impregnated freezing has research value and research significance.This paper mainly studies the effect of ultrasonic assistance on promoting impregnation freezing and the preparation of ultrasonic assisted control system for achieving precise control of impregnation freezing experiments.In the simulation software and experiments,the changes of temperature and freezing time during impregnation and freezing of silver carp pieces under the variables of ultrasonic intensity,ultrasonic auxiliary position and refrigerant flow rate were explored.When the flow rate of the refrigerant is 2 L/min the temperature drops the fastest,the maximum generation time of ice crystals is the shortest and the freezing time is the shortest With the increase of ultrasonic intensity,the freezing effect first increases and then decreases,and the freezing time first decreases and then increases,not the greater the ultrasonic intensity.When the ultrasonic intensity is 0.264 W/cm2,the temperature drops the fastest the ice crystal maximum generation zone time is the shortest,the freezing time is the shortest,the phenomenon of destroying the quality of fish meat is destroyed when the refrigerant flow rate is 2 L/min and the high ultrasonic intensity is 0.264 W/cm2.The ultrasonic auxiliary position had little effect on the impregnation and freezing of silver carp pieces,the temperature drop was similar,the maximum formation time of ice crystals was similar,and the freezing time was similar.According to the simulation requirements and experimental requirements,in order to achieve accurate control of ultrasonic assistance,PLC ultrasonic auxiliary system is designed to control ultrasonic intensity and refrigerant flow rate,and realize automatic control of ultrasonic and refrigerant flow rate,making refrigeration production more convenient And after PLCSIM simulation test,the functions of the ultrasonic assistance system are normal.