Researches On The Extraction Of Myofibirllar Proteins Of The Duck Muscle And The Gelation Properties

Modern researches have shown that duck meat belongs to green health food, whichowns high protein, low fat and low cholesterol. However, the duck meat processingtechnology is relatively backward which cannot utilize the nutritional value of the meat.Therefore, in this subject we use duck as raw material, mainly study the myofibrillar proteinwhich act the most key role in the meat protein. The research mainly study on the changes ofmyofibrillar proteins under various factors, and the influence of adding modified starch onproteins, and the effects of solubility of myofibrillar protein and functional characteristics ofmixture gels after using ultra-high pressure.The first part of this subject mainly researches the influence of various factors to thefunctional characteristics of protein gels, and then separately through the orthogonalexperiment using the water-retaining property and rigidity as metrics. In the end we get theresults of the optimum conditions. Among them, the optimum technological conditions ofsolution environment which impact water-retaining property of protein gel: pH6.5,0.8mol/L (NaCl concentration),40mg/ml (protein concentration); the best technologicalconditions of heating methods which affect rigidity of protein gel:80℃(heatingtemperature),30min (heating time),0.2℃/min (heating rate).Due to kinds of advantages owned by the modified starch relative to the native starchfor meat products, in this subject, we use four kinds of modified starch from different plantsand with different particle size, then add them to the extracted duck myofibrillar proteinswith different additive amount and different heating temperature to observe and measure thewater-retaining property, gel strength, rheological behavior, etc of the starch-protein gels.The results shows that at70°C, modified starch of potato and cassava plays a role ofpromotion in the composite gel system; influence on gel characteristics of corn modifiedstarch only slightly increases, relative to above two kinds of starch; while rice modifiedstarch has the function of negative growth to the composite gel system. Through thedetermination of the RVA map which shows the viscosity and pasting temperature by heatingthese four kinds of modified starch in aqueous solution and salt solution with differentheating rate, we observed that starch myofibrillar protein complex gel system may be relatedto starch viscosity and pasting temperature. The pasting temperature is lower, the influenceof the physical properties is better.Since the demands of consumers for food safety, nutrition, convenient, fast and freshincreasing every day, the ultra-high pressure technology is increasingly more popular by the food processing industry. This technology can reduce the loss of food nutrients caused byhigh heat, in addition, the pressure transmission speed is fast and uniform, the process issimple which also need less energy. Moerover, this technology can extend the shelf life ofthe food. Therefore, this project applies ultra-high pressure to the mixture which containedstarch and myofibrillar protein to explore how the ultra-high pressure solution affects thesolubility of myofibrillar protein and functional characteristics of mixture gels. The resultsshow that with the increase of the pressure level, the solubility of muscle fiber proteingradually increase and gain the maxmiun value in400MPa, which can be also confirmedby the SDS-PAGE electrophoresis assay. While for the starch-protein gels, pressure leveland the dwell time increasing will cause significant effect on the rigidity, chewiness,springiness and whiteness of gels.