Studies On The Influencing Mechanism Of High Hydrostatic Pressure Treatment On The Snakehead Actomyosin And Its Interaction With Other Biomolecules

High hydrostatic pressure(HHP)technology is a non-thermal processing technology emerging in recent years and has been applied in the field of food processing.In this thesis,the snakehead was selected as the main research object.The effect of HHP treatment on the properties of snakehead surimi gel was studied,and the changes of snakehead actomyosin(AM)structure during HHP treatment was analyzed.The interactions between sugar additive(xylooligosaccharide(XOS))/fatty acid(docosahexaenoic acid(DHA))with snakehead AM were further investigated.The research was conducted to clarify the correlation mechanism between HHP processing technology,AM structure,carbohydrate-protein interaction/fatty acid-protein interaction and food properties.The main results obtained are as follows:Firstly,the effect of HHP treatment on AM structure and function was studied.The results showed that when the holding time was 15 min,the pressure above 100 MPa significantly altered the secondary and tertiary structure of AM,which in turn caused changes in its properties and functional characteristics,and most of the changes were most significant when treated at 400 MPa for 15 min.Compared with non-pressurized AM,the solubility,the free sulfhydryl content and the surface hydrophobicity of AM treated at 400 MPa for 15 min increased by about 14%,34%,and 95%,respectively,while the angiotensin I-converting enzyme(ACE)inhibitory activity and the DPPH radical-scavenging activity increased by about 1.9 times and 10.66 times,respectively.Secondly,the effect of HHP treatment on the interaction between AM and other biomolecules(XOS or DHA)was investigated.The results showed that the HHP treatment(100-600 MPa,15 min)could enhance AM-XOS interaction or AM-DHA interaction,and the binding constants reached the maximum when treated at 400 MPa for 15 min.The fluorescence quenching of AM by XOS and DHA was mainly driven by hydrogen bonding and van der Waals forces.After being treated at 400 MPa for 15 min,the ACE inhibitory activity(46.96±3.95%)and DPPH radical-scavenging activity(69.35±1.04%)of the AM-XOS complex reached the highest values,which were approximately 2.0 times and 2.9 times that of the AM-sucrose complex,respectively.Finally,the effects of HHP treatment on the properties of surimi gel were studied.The results showed that the treatment of 400 MPa for 15 min had the most significant effect on the texture characteristics of surimi gel,in which hardness,springiness,chewiness,and cohesiveness increased by 3.00 times,1.61 times,5.96 times,and 1.23 times,respectively.The addition of XOS can effectively retain the L*,whiteness,and hardness of surimi gel and reduce the chewiness of surimi gel,which was more conducive to improve the properties of surimi gel than the addition of sucrose.HHP treatment(100-600 MPa,15 min)could improve the texture properties of surimi gel by changing the advanced structure of AM and the interaction of AM-XOS.