Study On Glutamine Transaminase Crosslinking Of Myofibrillar Protein And Gluten Protein Gel And Its Application

In this study,myofibrillar protein(MP)and wheat gluten protein(WG)were used as the study samples.Firstly,the effects of glutamine transaminase(TGase)on the gelation structure and functional properties of MP/WG were studied.Secondly,the effects of the different pre-emulsified soybean oil and lard on the structure and functional properties of TGase enzymatic MP/WG gel were studied.Finally,the effect of glutamine transaminase treatment on meat products with gluten protein added was studied.The study came to the following conclusions:The effect of TGase concentration on the properties of MP/WG gel was studied.The results showed that TGase(MP/WG=6:4,total protein content was 10%,TGase dosage was 90 U/g)could better catalyze the cross-linking of MP and WG protein.The gel has high storage modulus(G’),gel strength,water holding capacity and good structure.TGase enhanced intermolecular hydrogen bonds and hydrophobic interactions of MP/WG gels,leading to changes in the secondary structure of the gels.The contents ofα-helix conformation and β-turn conformation decreased,while the contents of β-sheet conformation and random coil conformation increased.TGase changes the protein structure and promotes the cross-linking between myofibrillar protein and wheat gluten protein.The effects of different proportions(0%,5%,10%,15% and 20%)of emulsify soybean oil(ESO)and emulsify lard(EL)in on TGase enzyme promotion of MP/WG composite gel were studied.The results showed that with the increase of ESO and EL,the gel hardness,elasticity and water holding capacity of emulsified soybean oil group and emulsified lard group were significantly increased(p<0.05).The hydrophobicity and hydrogen bonding between small molecular fat particles and protein were gradually enhanced,while the ionic bonding was gradually decreased.When the same proportion of fat was added,the gel properties of ESO group were better than that of EL group.When the addition of ESO or EL was more than 15%,the hardness and elasticity of MP/WG gel decreased,while the water retention and cohesion tended to be similar.Microscopic analysis showed a porous structure,the protein structure could not contain oil particles,and a small amount of oil particles spilled from the surface of the gel.The effect of TGase on meat products with gluten protein(low fat sausage and emulsified sausage)was studied.The results showed that TGase could significantly improve the stability of texture and energy storage modulus of low-fat and emulsified sausage,reduce the cooking loss rate of ground meat,improve the product structure.The product presented a stable state.In the low-fat sausage group,the addition of gluten protein slightly reduced the cooking loss of low-fat intestines.But protein aggregates appeared in the microstructure of low-fat sausage directly added with gluten protein.TGase could improve the phenomenon of uneven crosslinking.In the emulsified sausage group,the addition of emulsified soybean oil significantly increased the elasticity,hardness and water holding capacity of the emulsified sausage,decreased the cooking loss,and improved the structure of the emulsified sausage.