Effect Of High-voltage Electrostatic Field Combined With Refrigeration On The Quality Of Prawn(Metapenaeus Ensis)and Mechanism Research

High-voltage electrostatic field?HVEF?technology is a non-thermal processing method,which has the characteristics of simple equipment,low energy consumption and no pollution.It has been widely used in food processing such as freezing,thawing,drying and fresh keeping in recent years.HVEF technology in the postharvest is well developed,while in the aquatic products.The prawn?Metapenaeus ensis?was selected as the raw material,and the self-built HVEF equipment in clod chain system was used to study the HVEF technology in the prawn.In order to explore the potential of HVEF in the preservation of aquatic products by measuring the index of freshness change of prawn during storage.Additionally,the effects of HVEF on the biochemical properties of actomyosin and cathepsin activity were exploring to analyze the mechanism of action of HVEF and provide a theoretical basis for HVEF preservation technology of the prawn,so as to further expand the application range of the HVEF fresh-keeping technology.The results are shown as follows.1. The deterioration of the quality of the prawn was effectively delayed under HVEF treatment.Compared with the control group,the samples of the HVEF group showed better color and texture characteristics.The application of a HVEF was conducive to inhibiting biochemical reactions such as protein degradation,lipid oxidation,and microbial growth that occur during storage.In addition,as the voltage value increases,the better the preservation effect.Comprehensive comparative analysis showed that the combination of HVEF and cold storage can extend the shelf life of the prawn by more than 2 days.2. The denaturation of proteins was effectively inhibited by HVEF,and as the voltage increases,the better the inhibition effect.Among them,the increase of the surface hydrophobicity of the actomyosin during storage was inhibited under HVEF treatment,and the decrease of the salt solubility,Ca²⁺-ATPase activity and total sulfhydryl content were delayed after HVEF treatment.From the results of fluorescence spectroscopy,the HVEF treatment has a better effect to maintain the tertiary structure and conformation of actomyosin.From the electropherogram,it can be seen that the MHC optical density of the HVEF treatment group was significantly greater than that of the control group at the same time,and the change was relatively slow.It showed that the former could inhibit protein denaturation and degradation.3. With the extension of storage time,the activities of cathepsin L,B and H of the four groups of samples all showed an upward trend.The activity of cathepsin L changed the most,followed by cathepsin H,and cathepsin B changed the least.Cathepsin D showed an upward trend and then a downward trend,but the enzyme activity also increased slightly from the initial value.Cathepsin L plays the most important role in the hydrolysis of prawn protein.In addition,the HVEF was capable to inhibit the activity of cathepsin L and B.It has a certain effect on cathepsin H but has little effect,and basically has no effect on the change of cathepsin D activity.