Effect Of Transglutaminase-induced Cross-linking On Functional Properties Of Myofibrillar/Kidney Bean Protein Mixtures

The paper was to study the cross-linking reaction induced by transglutaminase which took place between chicken and kidney bean protein, and the effect of the cross-linking reaction on the protein’s important properties (including emulsifying properties and gelation). Moreover, the cross-linking reaction would be applied in food processing (preliminary development of new chicken meatball) and drug encapsulation (encapsulation of curcumin).In order to study the cross-linking conditions of the reaction between chicken and kidney bean protein, Determination of change in turbidity, SDS-PAGE and Gel filtration chromatography were used in different view. The results of those methods showed that MPI, KPI and MPI/KPI would be crosslinked by TGase and macromolecule protein could be formed; some small molecular protein and peptide in the protein mixtures could also catalyzied by TGase; Moreover, the cross-linking reaction took place not only between the homologous protein, but also heterologous proteins; preheating KPI would contribute to the cross-linking reaction, and the macromolecule protein would be formed in advance and yet be smaller.The emulsifying ability of mixture proteins improved significantly, but not continued to improve with TGase incubation time extension. And preheating KPI could not only enhance its own emulsifying ability, but also promote the emulsifying ability of the proteins formed by itself or MPI/KPI incubated with TGase. However, TGase had no effect on the emulsifying stability. The change of MPI/KPI with or without TGase showed the additon of KPI would weake the gel-forming ability of MPI, but the gelation could be improved notably by being incubated with TGase and/or preheating KPI. However, preliminary treating mixture proteins with TGase under gel-forming temperature was bad for their gelation.As to enzymatic cross-linking application in developing new chicken meatball, the optimum conditions to produce new chicken meatball were as follows:TGase concentration 0.24%, reaction time 65.62min, reaction temperature 43.63℃, kidney bean protein concentration 1.5%, and the gel hardness of chicken meatball reached 681.062g, which was much higher than that without TGase treatment. Moreover, preheating KPI could futher improve the hardness of new chicken meatball.As to enzymatic cross-linking application in drug encapsulaton, the conditons of TGase had a remarkable impact on the encapsulation yield of curcumin, and the optimum conditions were as follows:pro:TGase (TGase concentration)= 80:1, reaction temperature 45 ℃, reaction time 6h. Moreover, Different protein proportion had a slight influence on the encapsulation yield of curcumin; different wall/core ratio had a significant impact and the curcumin encapsulation yield reach highest-67.3% when the wall/core ratio was 5:1.