Effects Of High Hydrostatic Pressure On The Quality Of Eel Surimi And The Properties Of Myofibrillar Protein And The Correlation Between Them

As consumers pay more attention to food safety and nutritional value,the traditional food processing methods such as heating and cryogenic refrigeration could not meet the requirements of consumers.It is necessary to discover new food processing technologies.Due to its non-heating process,high hydrostatic pressure(HHP)technology attracts researchers5 attention.HHP could improve meat taste by changing physical and chemical properties of meat,therefore,it is very important to further study the mechanism of HHP treatment on aquatic products.In this study,eel was closed as the research object,and HHP(100-600 MPa,holding for 15 min)was used to treat the eel surimi and its myofibrnllar protein to analyze the effects of HHP on them and correlation between them.Firstly,the quality study of the eel surimi showed that HHP enhanced the hardness,chewiness,fracturability and gel strength,reduced the adhesiveness and increased water holding capacity of the surimi,which implied that the taste of the surimi is more delicious;Meanwhile,pressurized surimi had decreased redness and increased brightness/whiteness,which meant the appearance of the surimi looked like more cooked to stimulate consumers' purchase desire;Moreover,the ultrastructure of the surimi became tight and orderly under pressure,the size of the voids between the macromolecular aggregates was smaller,and the uniform surface morphology increased the gel strength of the surimi,which will make the surimi full of more chewiness when chewed by the teeth.These results indicated HHP significantly improved the gel quality of the surimi,and preferably preserved its flavor and nutrients.The surimi changes at 400 MPa are in line with consumers,expectations.Secondly,studies on the properties of eel myofibrillar proteins(MP)revealed that HHP changed its secondary and tertiary structure,a-helix and p-sheet turned to be random roil and P-turn.It showed 400 MPa had the most pronounced changes on MP.the spatial structure changes of the protein caused changes in their surface environment(oxidation of sulfhydryl groups,increase of non-polar groups,enhancement of hydrophobicity,reduction of solubility and the stability of the protein system),and affected their functions.It's found the angiotensin-converting enzyme(ACE)inhibitory activity of pressurized MP was significantly improved,and the highest value of 76.9%was obtained at 300 MPa,which was increased by 16.5%compared with that of non-pressure treatment.In addition,this study also explored the intrinsic mechanism of HHP inducing MP changes(MP is a complex protein containing 70%actin and myosin).The results indicated that actin and myosin had a certain interaction between them under 400 MPa pressure,and specific mechanism required further research.Lastly,it is analyzed that there is a correlation between the secondary structure of MP and surimi texture.It exists a negative relationship between surimi texture and a-helix/?-sheet,while a positive correlation between surimi texture and random coil/?-turn.Therefore,the change of MP structure under HHP affected the quality of eel surimi.Our research could provide theoretical basis for the HHP processing of surimi and the application of myofibrillar proteins in the food industry.