| Duck meat has a good flavor and high nutritional has been popular with consumers,its edible quality has been concerned by people all the time,the quality of duck meat is easily affected by storage,transportation and processing after slaughter,and the processing method has the most significant influence on the quality.Objective: based on duck as experimental object,three conventional heating methods were used(water bath?infrared and microwave heating),the effects of heating method and temperature on the quality of duck meat,physicochemical properties and structural properties of myofibrin were studied.Methods: duck meat was processed by water bath heating,infrared heating and microwave heating.then detect the duck meat quality(pH?color?water-holding?protein content?texture),the physicochemical properties of protein(emulsifying activity index,EAI? emulsifying stability index,ESI? surface hydrophobic? gel whiteness ? gel water holding capacity ? gel texture)and structural properties(carbonyl content,mercapto content,amino content,secondary structure),and analyze the correlation.Results:(1)with the increase of temperature,the pH of duck meat in the water bath and microwave group showed a significant upward trend(P<0.05),the infrared heating group pH is down after rising first,Brightness values(L*)a trend of increase significantly(P<0.05),yellow degree value(b*)increases first and then decreases,after 70 ? was not change regularly;The redness value(a*)first increases and then decreases;Hardness,chewiness and viscosity increased with the temperature,and the water bath group increased faster than the microwave and infrared group.Elasticity,resilience and cohesion showed a trend of increasing at first and then tending to be stable.On the whole,protein content showed a significant decrease trend contrary to temperature change(P<0.05),and the destruction effect of infrared heating on protein was relatively weak.(2)With the increase of temperature,the surface hydrophobicity of duck myofibrin increased significantly,and the effect of water bath heating treatment on the surface hydrophobicity was greater.EAI decreased,ESI increased first and then decreased,which is the best at 60 ?;The whiteness and hardness of myofibrin gel showed an increasing trend,the elastic first increases and then decreases,and the viscosity shows a weakening trend.The coagulability of the infrared and microwaveheating group increased first and then decreased,and that of the water bath group decreased.The hydrophobicity of the gel decreased first and then increased,and then decreased with the increase of temperature.The three heating methods all promoted protein denaturation to form a gel,and the microstructure of the gel formed was different.The gel formed in the water bath heating group was more uniform than that in the infrared and microwave groups,and the network structure was more compact.The results of correlation analysis showed that protein content and duck hold water were significantly positively correlated(P<0.05),and negatively correlated with pH(P<0.01),Protein's EAI was significantly positively correlated with water retention,protein content and protein's ESI of duck meat(P<0.05),the protein gel whiteness value was extremely significantly positively correlated with the L* value of duck meat(P<0.01),the gel hardness and duck hardness were positively correlated(P<0.05),the gel elasticity and duck elasticity were positively correlated(P<0.05),There was a significant negative correlation between the hydrophobicity of protein surface and the water hold up of duck meat(P<0.05),and a significant positive correlated with the L*value of the duck meat and the protein gel whiteness value(P<0.05).(3)With the increase of temperature,the secondary structure of duck myofibrin showed an ordered to disordered transition,the ? helix decreased,the ? folding increased in the infrared and microwave groups,the ? angle and random coil increased in the water bath group;Carbonyl value the overall rise,sulfhydryl value rise after falling first,minimum at 80 ?,sulfhydryl value under the condition of same temperature from big to small is the infrared group > water bath > microwave group,the amino value showed a trend of decrease of the whole.The results of correlation analysis show that the hardness of duck meat was extremely significantly negatively correlated with ? helix(P<0.01),and elasticity was extremely significantly positively correlated with random coil(P<0.01),The L* value of duck meat was extremely significantly negatively correlated with water holding up(P<0.01),and the a* value of duck meat was extremely significantly negatively correlated with the carbonyl value of protein(P<0.01),Protein's carbonyl value was negatively correlated with protein gel retention and ESI(P<0.05),extremely negatively correlated with protein EAI(P<0.01),positively correlated with protein surface hydrophobicity(P<0.05),and extremely positively correlated with protein gel elasticity(P<0.01).Protein mercapto group was extremely significantly positively correlated with protein EAI(P<0.01),and significantly negatively correlated with protein gel elasticity andpositively correlated with protein ESI(P<0.05).Random coil was extremely significantly positively correlated with gel retention and gel elasticity(P<0.01)and extremely significantly negatively correlated with EAI and ESI(P<0.01).SDS-PAGE analysis showed that myofibrin was decomposed to different degrees at different temperatures.The high-molecular weight protein was decomposed into small molecular polypeptides and amino acids.At the same temperature,the degree of myofibrin decomposition was from high to low is the microwave group > water bath group > infrared group.Conclusion: the three heating methods have different effects on the quality of duck meat and the physicochemical and structural properties of myofibrin.The physicochemical properties and structural changes of protein had significant effects on duck meat quality.Compared with water bath and microwave,infrared heating has a mild effect on the quality,physicochemical and structural properties of duck protein... |
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