Effects Of Different Modified Tapioca Starches On The Heat-Induced Gelation Properties Of Myofibrillar Protein

Heat-induced gelation of myofirbrillar proteins plays a important role on the texture, water holding capacity, rheological properties and other characters of meat products. The gelation properties of muscle protein are affected by heating temperature, pH, hydrocolloids and so on. Starch is an important biopolymer in foods, modified starch provided functional attributes that native starches cannot provide. It had been widely used in food industry. Temperature and content were two of important factors that influence gelatinizing properties of starch and gelation properties of myofibrillar protein. This study took the chicken breast as material, studied the effect of native starch and modified starches on myofibrillar protein heat-induced gels properties at different temperatures and starch contents, investigated the starches on the quality characteristics of chicken sausages. The results of the study stated as follows:1. The properties of modified starches and their influence on the thermal and rheological properties of myofibrillar proteinThe characteristics of native starch and modified starch(acetate starch, cross-linked esterified starch and phosphate starch), the thermal and rheological properties of starch/myofibrillar protein composites were investigated. The results showed that the granule size of modified starches is smaller than the native starch. The phosphate starch was more transparent than native starch and other modifies starch. The gelatinization properties and rheological characteristics were affected by the properties of starch and the ratio of amylose and amylopectin. The cross-linked esterified starch had the lowest gelatinization temperature and the storage modulus (G’) value is higher than the G’of native starch and other modified starches. The starch/myofibrillar protein composites yielded a higher To and Tp for starches compared with starches alone. Native starch and modified starch improved the storage modulus of myofibrillar protein after the temperature achieve or above their respective gelatinization temperature, cross-linked esterified starch had the highest storage modulus of gels, followed by acetate starch, The phosphate starch/myofibrillar protein composite had the lowest G’.As the content of starches increased, The G’increased during heating.2. The effect of starches on properties of gels under different temperature and starch contentThe effect of native starch and modified starches on WHC, hardness, springness, the state of water(T2relaxation)and microstructure of gel at different temperature and starch content were investigated. The results showed that the effects of starches on the WHC, hardness and springness were related with the starches gelatinization temperature. Starches improved the WHC, hardness and springness of the myofibrillar protein heat-induced gels after the temperature achieve or above their respective gelatinization temperature. The WHC of myofibrillar protein gel with cross-linked esterified starch was higher during heating. When the temperature above70℃, the WHC of myofibrillar gel with native starch, acetate starch and phosphate starch significantly increased. Cross-linked esterified starch improved the hardness and springness of gel before the temperature achieve70℃. When the temperature above70℃, the add of cross-linked esterified starch and acetate starch significantly increased the hardness, While the springness of gel with native starch and modified starch were not significantly different. Compared with the control group, the T21peak area proportion of gels with starches increased(P<0.05). At the same temperature, T22peak area proportion of gels with modified was higher than the gels with native starch except gels with phosphate starch, while T23peak area proportion was lower than the gels with native starch. The WHC of gels increased as the content of starch increased, the WHC of gel with cross-linked esterified starch was higher at different content. As the content of starches increased, the hardness and springness of gel increased. The hardness of gel with phosphate starch was lower than the gels with native starch and other modified starches. The springness of gel with cross-linked esterified starch was higher at different content. As the content of starch increased, T2b and T21peak area proportion of gels increased, while T23peak area proportion decreased. T22peak area proportion of gels with modified starches was higher than the gels with native starch at same content. Scanning electron microscopy revealed that cross-linked esterified starch granule swelled at60℃, native starch and modified starches swelled and filled in the protein structure network when the temperature achieved70℃。 Using the protein staining method, it appeared that protein matrix formed a continuous phase, while the starch were coating on the peripheral surface of protein structure or filled in the voids of the protein structure network.3. The effect of modified starches on the qualities of chicken sausageThe effect of different tapioca modified starches and native starch on the quality characteristics of chicken sausages were investigated. Three kinds of modified starches including acetate starch, cross-linked esterified starch and phosphate starch were added during chopping respectively,the cooking yield, color, texture profile analysis(TPA)and sensory characteristics were measured. The results showed that modified starch had better role than native starch in sausage, Different modified starches had no significant affect on cooking yield(P>0.05). The color L*, a*and b*were affected by the addition of different modified starches. The hardness, chewiness and cohesiveness of sausages with modified starches was significantly increased in comparison to sausage with native starch(P<0.05) The hardness of chicken sausage with modified starches remained stable during storage, while the hardness of sausage with native starch exhibited a trend of increase. The sensory evaluation showed that the product containing modified starch had higher sensory scores in comparison to the products with native starch. Overall, the modified starch could improve the quality attributes of chicken sausage.