Effect Of Medium Electric Field Treatment On The Damage Of Apple Tissue Structure And Fresh Juice Quality

China's apple production ranks first in the world,but the proportion of deep processing only accounts for 20% of the output.Apple fresh juice is nutritious and healthy,and is widely loved by people.The medium electric field treatment can damage the apple tissue cells and accelerate the processing efficiency of apple juice.However,the mechanism of the damage of apple tissue structure is still unclear,and the effect on the juice yield and quality of fresh juice is not clear.In this paper,the red Fuji apple tissue treated by the medium electric field was used as the research object.The cell membrane integrity was detected by electrical impedance mapping method.Combined with cell wall component detection and cell microstructure observation,the damage of apple tissue cells was explained by the treatment conditions of the medium electric field.The influence of the medium electric field treatment conditions on the juice yield and quality of fresh juice and the establishment of a linear model.The main conclusions of the paper are as follows:(1)The effect of medium electric field treatment on the integrity of apple cell membrane was studied.The medium electric field treatment will seriously damage the integrity of the apple cell membrane.After the medium electric field treatment,the impedance and phase angle of the apple tissue are much smaller than that of the untreated,and the cell membrane capacitance is only 1/25?1/5 of the fresh sample.As the treatment field strength increases from 40V/cm to 80V/cm,the extracellular resistance decreases and the internal resistance increases,the cell membrane capacitance decreases,and the cell membrane integrity decreases.As the treatment frequency increases from 50 Hz to 800 Hz,the cells increase.The external resistance first decreases and then increases,the internal resistance decreases,the cell membrane capacitance increases,and the cell membrane integrity increases.As the treatment temperature increases from 45°C to 65°C,the extracellular resistance and internal resistance decrease simultaneously,and the cell membrane capacitance decreases.Reduced.Reduced cell membrane integrity.(2)The effect of medium electric field treatment on the cell wall components of apple was studied.The medium electric field treatment will decompose the cell wall and the intercellular layer.As the treatment field strength increases from 40V/cm to 80V/cm,the water-soluble pectin content of the cell wall increases,ionic pectin and covalently combined fruit.The content of gum and hemicellulose decreased,and the cellulose content remained basically unchanged.As the treatment frequency increased from 50 Hz to 800 Hz,the content of the cell wall decreased first and then increased;with the treatment temperature from 45°C to 65°C Increasingly,the content of water-soluble pectin,ionic pectin,covalently combined pectin and hemicellulose in the cell wall decreased,and the cellulose content remained basically unchanged.(3)The effect of medium electric field treatment on the damage of apple cell microstructure was studied.With the increase of field strength in the medium electric field,the cell membrane perforation of apple cells is severe and close to the cell wall.With the increase of the frequency of the medium electric field treatment,the cell membrane damage of apple cells becomes smaller and the cell membrane shrinks seriously.When the temperature of the piezoelectric field is increased,the cell membrane of the apple cell shrinks seriously and gradually decomposes and disappears.The analysis shows that the electric field is the main influencing factor of cell membrane damage,and the temperature change caused by the medium electric field treatment will cause the tear of the cell wall structure,which is the main influence of the cell wall structure damage,and the medium electric field treatment will decompose the apple cell wall component.Destroy the structure of the cell wall.(4)The effect of medium electric field treatment on juice yield and quality of apple fresh juice was studied.With the increase of the treatment temperature and electric field strength of the medium electric field and the decrease of the electric field frequency,the juice yield of apple fresh juice increased by 4% ? 10% compared with untreated;the turbidity increased by 1% ? 44% compared with untreated;The L value of fresh apple juice is increased,the color is brighter and the browning degree is reduced;however,the pH and soluble solid content of fresh apple juice remain basically unchanged.A linear regression model of temperature,electric field strength and electric field frequency and juice yield and turbidity of fresh apple juice was established by using the experimental design method of multiple linear regression.It provides reference for the treatment of fresh apple juice in the medium electric field.