The Study On Sterilization And Additives Influenced The Texture Of Tilapia Sausage

At present, surimi products are mainly sold in the form of refrigerating/frozen storage,surimi products stored at room temperature after thermal sterilization have been reported andmarketed, while there is a problem that the deterioration of the quality, wherein the mostintuitive performance is the decrease of texture. But there are few reports on the mechanismof them. In order to study the influence of different sterilization conditions on the texture oftilapia sausage, the following studies were carried out by using tilapia surimi as raw materialand the sausage of tilapia as research object, and assessed their impact under the thermalsterilization. The following results were achieved:1. The different temperature-time combination effects on texture indicators, heatresistance characteristic value and chemical bonding indicators of tilapia sausage were studied.Results showed that the gel strength、TPA (texture profile analysis) indicators and waterholding capacity all decreased with the sterilization temperature (105~121.1℃) and thesterilization time (14~20min) increasing. In115~121.1℃, they decreased dramatically.When F0values were in3,5,7minutes, the above indicators fell more uniformly. Thedisulfide bond、non-disulfide covalent bond (ε-(γ-glutamyl)lysine bond) and hydrophobicinteraction were the main chemical bonding maintaining surimi gel structure at hightemperature conditions and the decreasing tendency was consistent with the texture indicators.Therefore, the above three kinds of chemical bonding were damaged in the high temperaturetreatment, which were the reason for the texture indicators becoming poor.2. The influence of different starch (types for potato starch、tapioca starch、modifiedtapioca starch) on the texture indicators and the chemical bonding indicators of tilapia sausagewith thermal sterilization. Results showed that when F0values were in3,5,7minutes, fromthe perspective of outside filling to improve the texture, the starch-surimi gel systemconforms to the "packing effect model" hypothesis. The network structure on the basis ofdisulfide bond, ε-(γ-glutamyl)lysine bond and hydrophobic interaction were destroyed, starchlost the filling and extrusion action, so gel strength, TPA indicators, water holding capacity oftilapia sausages with starch were significantly decreased, and the decreasing degree would bedifferent according to the starch types. The potato starch and modified tapioca starch wasbetter than tapioca starch.3The influence of carrageenan (volume of addition is0.1%、0.2%、0.5%) on the textureindicators and the chemical bonding indicators of tilapia sausage with thermal sterilization. Results showed that When F0values were in3,5,7minutes, from the perspective of outsidefilling to improve the texture, crrageenan significantly increased hydrophobic interaction ofsausage. The destruction degree of gel strength, TPA indicators, water holding capacity haddeclined, and in the range of0.1%~0.5%, with the increasing of concentration, the texturewould be better.4. The influence of different transglutaminase (TGase)(types for TG-B, TG-K, TG-AK)on the texture indicators and the chemical bonding indicators of tilapia sausage with thermalsterilization. Results showed that, from the perspective of inside cross-linking to strengthenthe texture, the sausage with TGase significantly strengthened ε-(γ-glutamyl)lysine bondcross-linking, so the gel strength, TPA indicators and water holding capacity of surimi-TGasehad been improved, and the effect of TG-B was the most evident.5. In order to study the influence of compound additives on the texture of tilapia sausagewith thermal sterilization and to further discuss the change after adding the combinationbetween carrageenan and TGase. Results showed that tilapia sausage with the abovecompound additives in the gel strength, hardness, resilience, water holding capacity weresignificantly higher than not adding samples, but the improvement effect of internal cohesionwas not significant. Compared to the sausage individually adding carrageenan, the gelstrength and resilience were significantly improved, cohesion was not increased significantly,hardness and water holding capacity were decreased. Compared to the sausage individuallyadding TG-B, its hardness, resilience and water holding capacity were increased significantly,and the upgrade of gel strength and cohesion was not significant. The gel strength andhardness D value of sausage with the above compound additives were significantly increasedthan not adding samples, in the range of105~125℃, the rate of increasing reached54.4%~134.4%and37.40%~76.67%, respectively, and it is more apparent on the heatresistant of gel strength. The heat resistance was significantly improved because thecorresponding Z values were increased by2.7℃and1.4℃, respectively. The damage extentof hydrophobic interactions and non-disulfide covalent cross-linking on the sausage with theabove compound additives was significantly decreased, while the extent of the damage to thedisulfide bond was not changed significantly.