Effects Of Enhanced High Voltage Electric Field-Assisted Freezing System On Pork Freezing

High voltage electrostatic field assisted freezing is an international cutting-edge research subject in the field of freezing.Due to its advantages of energy saving,high freezing rate and good freezing effect,it had received high attention from scholars in the field of refrigeration in recent years.However,the bottleneck of this technology is that the processing capacity of frozen samples is very small,that is,the effective processing space for samples is very small,which is far from meeting the requirements of industrial refrigeration.Moreover,the bottleneck of this technology has become a difficult problem in the field of refrigeration,which also hinders the further development of this technology.This topic was to focus on the difficult problems in the forefront of science and technology in the field of high-voltage electrostatic field refrigeration and carry out research work to break the bottleneck of sample handling capacity of high-voltage electrostatic field refrigeration technology.In this paper,UHPC-HVEFF and LPA-HVEFF were first developed.The freezing behavior of pure water was compared of the two systems,and the influence of strengthening the system of high voltage electrostatic field on the freezing characteristics was explored.Secondly,pork tenderloin was taken as sample,the effects of enhanced high-voltage electrostatic field on frozen pork tenderloin were investigated.Finally,the pork tenderloin frozen by 6 kV under the UHPC-HVEFF system and the pork tenderloin directly frozen in the refrigerator were used for the next frozen storage experiment to further explore the effects of the enhanced high voltage electrostatic field system combined with the glass transition temperature on the storage characteristics of pork ice crystals.The conclusions are as follows:1.According to the pure water freezing curve,compared with the LPA-HVEFF system,the UHPC-HVEFF system had a higher ability of accelerating freezing,and the variation degree of each freezing parameter was more obvious than that of the LPA-HVEFF system.Moreover,when the UHPC-HVEFF system was applied at 9 kV,compared with the control group,the degree of supercooling decreased by 90.3%,which had not been reported in all previous relevant literatures.According to analysis by COMSOL software,the intensity of electric field inside the UHPC-HVEFF system was 12.35 times on average and 18.52 times at the maximum than that of the LPA-HVEFF system.2.Compared with the pork tenderloin treated under-25? refrigerator freezing condition,the quality of pork tenderloin was better maintained under the UHPC-HVEFF system,and each quality index was optimal at 6 kV.However,when the voltage further was increased to 12 kV,the microstructure was inferior to that of 6 kV.The reason may be that the high electric field intensity affected the characteristics of the cell itself.3.The measured glassy transformation temperature of pork fillet was-15.1?.Enhance the storage temperature below the system of high voltage electrostatic field,refrigeration and glassy transformation can effectively improve the water retention and texture characteristics of pork fillet,reduce the degree of protein denaturing,and slow down the migration and loss of water.Under the same pre-freezing condition,the volume of ice crystals was increased obviously with the increase of freezing temperature during the freezing storage period.Under the same freezing storage temperature,the ice crystal area,relative ice area and equivalent circle diameter can be reduced and the ice crystal roundness can be increased in the early freezing process with 6 kV enhanced high voltage electrostatic field.In the early stage of freezing storage,the synergism of the high voltage electrostatic field in the process of freezing storage was effective in maintaining the roundness of ice crystals and slowing down the growth rate of ice crystals.On the 40 th day of storage,the negative effect of-15? storage condition on cells exceeded the positive effect of synergistic enhancement of high voltage electrostatic field during freezing process.