Study On The Effect Of Photons On Bovine Serum Albumin

Protein is one of the important components in food,which affects the quality of food.Studying the effect of photon preservation technology on protein is an important basis to reveal its preservation mechanism.In this study,bovine serum albumin(BSA)was treated for 7 days at 4? by photon,and during the experimental period,the physical and chemical properties,spatial structure,glycosylation and enzymatic activity of BSA were detected.The effect and mechanism of photon on BSA are explained from physical and chemical changes,structural changes and digestive characteristics changes,which provides a strong theoretical support for the application of photon in food preservation.The main contents include:(1)The physical and chemical properties of BSA were measured.It was found that the surface hydrophobicity,emulsification stability,foaming stability and foaming stability of BSA could be significantly improved by photon treatment under the experimental conditions.However,the concentration of protein solution did not change significantly compared with the control group.These results indicate that photon treatment can improve the physical and chemical properties of BSA to a certain extent.(2)SDS-PAGE,infrared spectroscopy,circular dichiroism and fluorescence spectroscopy were used to analyze the spatial structure changes of proteins.SDS-PAGE electrophoresis showed that the primary structure of the protein remained unchanged.Infrared spectroscopy and circular dichroism analysis showed that photon treatment of bovine serum albumin could affect its secondary structure content change.Alpha helix and beta folding would decrease,irregular curl would increase,and the whole protein tended to be loose.At the same time,it is found that the vibration intensity and chemical environment of chemical bonds with different structures are also changed,and their sensitivity to photon is different for different functional groups.Endogenous fluorescence and synchronous fluorescence analysis showed that after photon treatment,the tertiary structure of bovine serum albumin changed first,the concentrated area of the change was the hydrophobic center of the protein.It is concluded that the photon treatment of BSA will change its tertiary structure first and then lead to the loosening of the secondary structure as a whole,and the change region of the whole protein is concentrated in the active center of its hydrophobic region.(3)Analysis of glycosylation products.It was found that the content of free amino group decreased and the degree of grafting increased after photon treatment.The main reason is that the active center of BSA tends to loosen due to the treatment of photonr which exposes more reactive groups and promotes the glycosylation reaction.That is to say,photon processing may improve the processing properties of protein to some extent.(4)Bovine serum albumin(BSA)was hydrolyzed by trypsin in vitro,and the distribution of enzymatic products was analyzed by SDS-PAGE.The changes of the content of enzymatic products were analyzed.It was found that photon treatment inhibited the enzymatic activity of BSA.The amount of enzymatic hydrolysate was reduced.The results showed that photon treatment could decrease the digestive activity of bovine serum albumin.The results show that the photon treatment does not affect the stability of the primary structure of BSA,but mainly affects the changes of the tertiary structure and secondary structure of BSA.With the prolongation of photon processing time,the spatial structure of the hydrophobic center region will be loosely oriented,and the whole protein will be unfolded.In this process,some hydrophobic groups buried in the interior will be exposed,resulting in changes in their physical and chemical properties.At the same time,loose structure is beneficial to glycosylation,improving its processing characteristics and affecting its enzymatic activity.