| The thawing experiment of frozen beef were carried out changing voltage,electrode distance,needle spacing and the dielectric barrier discharge in the multiple needle-to-plate electrode systems in order to comprehensively investigate the high voltage electric field thawing characteristics and mechanism.The thawing characteristics,quality parameters of beef during thawing were measured.The subtle changes in the high voltage electric field discharge were recorded using a digital camera and an emission spectrometer.The changes in the chemical structure of beef were detected using infrared spectrum and scanning electron microscopy.The results indicated:Electrode distance and voltage have significant influence on thawing rate.The influence of the high voltage electric field in the beef center temperature range from-3 °C to 0 °C on the thawing characteristics is larger than the control.The electrode distance and voltage have significant influence on color,loss rate and quality parameters.By scanning electron microscopy,it was found that the high voltage electric field changed the chemica l structure of beef during thawing.During the thawing process,the ionic wind and nonuniform electric field have different effects on the thawing characteristic.The needle spacing has important influence on thawing process of beef.With the change of voltage,thawing characteristics and quality parameters of beef changed.From infrared spectrum,the absorbance of beef after high voltage electric field treatment was higher than that of the control.By analyzing the double index sequence,it was found that the high voltage electric field has a great influence on the chemical structure of beef.By the secondary structures of protein of beef,it was found that the energy generated by high voltage electric field will cause the protein to unfold and weaken the hydrogen bond,leading to the destruction of the ordered structure.The response surface method was used to analyze the electric field parameters such as voltage,needle spacing and electrode distance.The optimal parameters of high-volta ge electric field thawing were obtained: the voltage was 28 k V,the needle spacing was 8 cm,and the pole spacing was 10 cm.Under this condition,not only the thawing time was short,the thawing speed was fast,and the drip loss and water holding capacity were better,the product quality was better.By the digital camera and the emission spectrometer,it was found that the phenomeno n of discharge increase gradually,the ionic wind speed and the types of ions increase gradually with increasing voltage.Under the action of dielectric barrier discharge,with the increase of voltage,the thawing speed and thawing quality of beef increased gradually.The dielectric barrier discharge had a significant effect on the chemical structure and the secondary protein structure of beef during thawing according.By the experimental study on the thawing of beef under different experimenta l conditions in the high voltage electric field,it was found that the change rule of high voltage electric field thawing of the thawing characteristics,quality parameters and the chemica l structure of beef.This provides a theoretical basis and practical guidance for the in-depth understanding of the influence parameter characteristics and thawing mechanism of high voltage electric field thawing technology.This provides a theoretical basis and practical guidance for the in-depth understanding of the influence parameter characteristics and thawing mechanism of high voltage electric field thawing technology,improving the shortcomings of high voltage electric field thawing technology and improving the thawing efficiency. |
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