Studies On The Structure And Function Of Tropomyosin And Eel Balls Quality Treated With Ultrahigh Pressure Technology

Ultrahigh pressure technology(UHP),a new type of physical processing technology,has the advantages of quickness,convenience,low energy consumption and weak side effects,and it has received extensive attention in the food processing industry This paper studied the effects of UHP on the structure and function of tropomyosin as well as the quality of eel balls.The relationship between the quality of eel balls and the spatial structure of tropomyosin was also explored when treated with UHP.Firstly,the effect of UHP on the structure of tropomyosin was investigated.The results showed that the content of ?-sheet in tropomyosin decreased from 23.15±2.05%to 10.7±0.99%under 200-400 MPa treatment,while the content of p-turn increased from 13.70±1.41%to 16.2±1.13%,and random coil had an increase from 17.60±2.80%to 29.35 ± 0.21%,respectively.These results indicated that the ?-sheet was transformed into ?-turn and random coil under this pressure.The content of a-helix decreased from 45.55±0.64%to 40.4±2.33%under 500 and 600 MPa treatments,while the ?-sheet and P-turn increased to 15.2±0.99%and 18.45±1.16%respectively,indicating that the a-helix unfolding transformed into ?-sheet and ?-turn under this pressure.With the increase of pressure,the surface hydrophobicity of tropomyosin increased and the content of sulfhydryl group decreased.Secondly,the effect of UHP on the texture characteristics of eel balls was studied.The results showed that the texture parameters of eel balls were significantly improved after UHP,and reached the maximum under 400 MPa.After 500 and 600 MPa treatment,the surface morphology of eel balls was significantly improved.The results showed that the texture parameters of eel balls were negatively correlated with ?-helix,?-sheet and sulfhydryl group,but positively correlated with ?-turn,random coil and surface hydrophobicity.Thirdly,the effects on the function of tropomyosin with UHP was explored.It showed that the ACE inhibitory activity of tropomyosin decreased from 25.99±4.0%to 10.46±1.2%as the pressure increasing from 200 MPa to 400 MPa.These results showed that ACE inhibitory activity was positively correlated with the P-sheet.Finally,the effects of linoleic acid on the structure and function of tropomyosin were explored.Linoleic acid affected the polar environment of tropomyosin,resulting in the destruction of its secondary and tertiary structures,and the growth rate of TBA value of linoleic acid increased significantly.The results showed that tropomyosin accelerated the oxidation rate of linoleic acid.The binding force between linoleic acid and tropomyosin was weak,and the interaction between linoleic acid and tropomyosin was mainly van der Waals force and hydrogen bond.