| Myofibrillar protein（MP）is one of the most important functional proteins in meat products,which occupies the highest proportion of muscle protein.Therefore,it plays a decisive role in the quality of meat.However,protein oxidation occurs frequently in life,leading to a deterioration of quality.To improve the edible quality of meat products,cereals such as oats and barley are gradually applied to the meat industry,which not only enriching the taste and flavor but making the nutrition more balanced of meat products.At the same time,natural antioxidants in cereals also have an important impact on the gel properties and texture quality of meat products.Phenolic acids in cereals can inhibit the oxidation of adipose and protein,which has become an important direction of meat product processing.Feruloyl Oligosaccharides（FOs）extracted from corn bran were selected as an additive to explore its regulation of myofibrillar protein oxidation and its influence on protein structure and functional properties.The main research contents are as follows:1.Pork myofibrillar protein was chosen as the experimental material,the 0,0.05,0.1,0.5,1,5,10 m M H2O2 under the action of oxidative MP by measuring changes of side chains,surface hydrophobicity,solubility,emulsification,and the gel properties.Results showed that the moderately oxidized concentration of H2O2 was determined to be 1 m M.2.Feruloyl oligosaccharides was chosen to regulate the moderate oxidation of MP and investigate the effect on the structure of the protein.Sidechains,secondary structure,tryptophan,surface hydrophobicity,thermal stability,solubility,particle size,zeta potential,and electrophoresis were also determined.The results showed that theα-helical content was decreased and the protein was well cross-linked by oxidation,but the solubility,tryptophan fluorescence intensity,and thermal stability were decreased.After adding 50～100μmol/g FOs to the mixed system,it acted as an antioxidant,which increased the content of sulfhydryl,free amino,andα-helical content,cut down the content of carbonyl,surface hydrophobicity（P<0.05）.Besides,the fluorescence intensity of tryptophan and solubility increased,the protein structure approached stable and the interaction between protein and water was strengthened so that the particle diameter and zeta potential of the mixed system tended to be stable.However,excessive FOs（150～200μmol/g）induced covalent cross-linking between oxidized protein or FOs and MP to form polymers.According to the analysis of electrophoresis results,the polymers are mainly formed through disulfide bonds.Therefore,the appropriate addition of FOs can exert its antioxidant effect,but excessive FOs induced further unfolding of the oxidized protein structure and cross-linking and aggregation with the protein.3.Feruloyl oligosaccharides was chosen to explore the gel properties of oxidized MP.It was studied by measuring the effect of the gel strength,water holding capacity,rheological properties,microstructure changes,water distribution,and chemical forces of the heated induced gel.The results showed that the gel strength and water holding capacity of the mixed gel was the largest at 50μmol/g of FOs,which was consistent with the changes in the storage modulus and loss modulus.At this time,the water in the gel structure was easy to keep,the three-dimensional network structure of the gel was the most intensive and the chemical bonds were mainly hydrophobic to maintain the gel structure.When the addition of FOs was up to 100μmol/g,the gel strength and water holding capacity of the mixed gel was significantly reduced,as long as the viscosity and elasticity.Excessive FOs would cause over cross-linking of protein,weaken the water retention capacity so that the gel structure got collapsed and porous so that disulfide bond became the main chemical force of gel formation at this time.The experimental results showed that the appropriate addition of FOs could improve the water binding ability of the gel and alleviate the adverse effects of oxidation on the gel properties of MP. |
