Study On The Functional Properties Of Myofibrillar Protein From Several Species

The functional properties of proteins of meat involved emulsifying properties, physicochemical properties and gel properties. The myofibrillar protein of muscle played an important factor in the action of protein functional properties. Previous research was mainly focus on the effects of solution environment(such as pH, ionic strength), external environmental factors(such as temperature) and additives on the functional properties of myofibrillar. And the research on the functional properties of different kinds of meat and muscle was well-studied, but the mechanism which caused the difference in functional properties had not been studied widely. The purpose of this research was to compare the difference of emulsifying properties and physicochemical properties of myofibrillar protein from pork, chicken and beef, and to analyze the mechanism which caused the difference in emulsifying properties through the results of physicochemical properties. And the investigation which compared the difference of gel properties through analyzing the composition and content of myofibrillar protein, and combining with the results of low-field NMR and rheological properties, was also studied.1The comparison of the emulsifying and physicochemical properties of myofibrillar protein from different kinds of meatThe investigation was undertaken to compare the emulsifying and physicochemical properties of myofibrillar protein from several species(pork and chicken and beef), and delve the reason why the emulsifying properties was different. The emulsifying and physicochemical properties was influenced by the protein concentration. The solubility and emulsifying capacity increased with the increment of protein concentration which changed from1mg/mL to8mg/mL, but change of the two index was not significant when the protein concentration was higher than8mg/mL(P>0.05). The viscosity significantly increased with the increment of protein concentration (P<0.05), but the emulsifying activity index decreased with the increment of protein concentration. When the protein concentration was lower than5mg/mL, the change of the emulsifying stability index was not obvious(P>0.05). When the protein concentration was higher than5mg/mL, the emulsifying stability index increased with the increment of protein concentration, and the emulsifying stability index of chicken increased indistinctively when the protein concentration was higher than8mg/mL. Under the same protein concentration, the emulsifying and physicochemical properties(except of the surface hydrophobicity) of chicken was higher than the other two kinds of meat, pork was higher than beef(P<0.05), except that the emulsifying activity index of chicken and pork had not significant difference at10mg/mL (P>0.05). The surface hydrophobicity of chicken was the lowest, beef was higher than the other two kinds of meat(P<0.05). There was a significant positive correlation between emulsifying capacity and solubility(P<0.01), as well as the correlation between emulsifying stability index and viscosity(P<0.01), and emulsifying capacity was influenced by the surface hydrophobicity.2The comparison of gel properties of myofibrillar protein from different kinds of meatThis work was to compare the gel properties of myofibrillar protein from different kinds of meat, and investigate the effects of adding different proportion of oil on the gel properties through analyzing the results of low-field NMR and rheological properties. The result showed that the chicken myofibrillar protein had the highest gel hardness, gumminess, chewiness and water retention, while the pork had the lowest (P<0.05). When the three kinds of protein was heated, a new relaxation component corresponded to the free water appeared, and the T23peak area of chicken was significantly lower than the other two kinds of meat(P<0.05), which meant the better water holding. The pork had the largest T23peak area and the worst water holding capacity(P<0.05). The addition of oil had no significantly effect on the relaxation time T22, but created the other new relaxation component T21and caused a significant reduction in the T23peak area(P<0.05). With the increment of the amount of added oil, T22peak area gradually reduced and the peak area of T21gradually increased. During the heating, the storage modulus G1significantly increased with the increment of the amount of added oil (P<0.05). The chicken myofibrillar protein had the highest storage modulus G’ and the maximum gel strength under the condition of the same amount of added oil and temperature, the storage modulus G’of beef myofibrillar proteins was significantly higher than that of pork (P<0.05).In summary, the emulsifying properties of chicken and pork and beef were significantly different because of the difference of physicochemical properties. And the protein composition and the content of constituent caused the difference of gel properties of the three species. The emulsifying properties and physicochemical properties (except of the surface hydrophobicity) and gel properties of chicken myofibrillar protein were higher than the other two species. The emulsifying properties and physicochemical properties (except of the surface hydrophobicity) of pork were higher than beef, but the gel properties of beef were higher than pork.