Generating Mechanism Of Maillard Reaction Products From Ovalbumin And Glucose By Microwave Treatment

Ovalbumin and glucose were used as raw materials,using the traditional heating and microwave heating to make the maillard reaction products of OVA- glucose, and the physicochemical property, structural characteristics, main components and nutrition and safety of glycated OVA were carried on the systematic study, to supplement and perfect the basic theory of microwave effect on protein mail lard reaction, and provide the theoretical guidance to the application of protein maillard reaction in food industry.The results of browning degree, free amino group and SDS-PAGE showed that there was a grafting reaction based on maillard reaction mechanism between O VA and glucose under dry heat treatment. With the increase of protein content, the maillard reaction degree gradually reduced. In general, in the aspect of increasing the degree of maillard reaction, microwave heating is better than traditional heating. The result of p H showed that there was a production of organic acids and a consumption of amino for glycated OVA compared with native OVA, and compared with traditional heating, the decrease degree of pH was more higher under microwave treatment. The emulsifying properties and foaming properties of glycated OVA have improved, and when the mass ratio of OVA and glucose was 1:1, the emulsifying properties and foaming properties were more higher than other ratio. After maillard reaction between OVA and glucose, the turbidity decreased of glycated OVA compared with the native OVA. This result showed that maillard reaction can improve the solubility of protein, and mainly can improve solubility around the isoelectric point of protein.After maillard reaction between OVA and glucose, the fluorescence intensity decreased, surface hydrophobicity increased. These results showed that during the process of maillard reaction, the tertiary structure of OVA has changed, lead to some aromatic amino acid residues were sheltered, hydrophobic groups which located in internal molecular were exposed. The content of sulfhydryl groups increased showed that during the process of maillard reaction, the secondary structure of OVA has changed, and there was an unfolding phenomenon. The content of carbonyl groups increased showed that during the process of maillard reaction, the senior structure of OVA has changed, resulted in the denaturation of protein. The ultraviolet absorption spectrum peak of glycated OVA increased, showed after maillard reaction, new chromophore such as pyrrole, furan compounds were introduced in the protein structure.After maillard reaction between OVA and glucose, not only some beneficial substances were formed, but also generated some harmful substances. This thesis mainly studied the content of melanoidin, fructosamine, carboxymethyl lysine(CML) and HMF. The results showed that compared with the traditional heating, the content of melanoidin, fructosamine, carboxymethyl lysine(CML) and HMF were more higher under microwave heating. When the ratio of OVA and glucose was 1:1, the content of melanoidin, fructosamine, carboxymethyl lysine(CML) and HMF were more higher than other ratio. The results showed that under the condition of microwave heating as well as the lower protein proportion, the degree of maillard reaction can reach the end phase more faster.After maillard reaction between OVA and glucose, antigenicity decreased significantly, especially under the condition of microcwave treatment. When the ratio of OVA and glucose was 1:1, the extent of decrease for antigenicity was more higher than other ratio.