Study On The Regulation Mechanism Of Ultrasonic Modification On The Functional Properties Of Myofibrillar Protein Extracted From Fish

Meat is an essential protein source for human daily food consumption,and mammalian meat,such as cattle,sheep,and pork,accounts for a large proportion of the market sales.However,in recent years,due to the influence of mad cow disease,African swine fever,and religious restrictions on mammalian meat,the sales of mammalian meat products have decreased.Fish has good economic benefits,high nutritional value,with no zoonosis,which gains increased attention year by year.The research and development of fish-related products have become a hotspot.The content of myofibrillar proteins(MPs)in muscle is as high as 60%,and its structure and properties determine the processing characteristics of meat products.However,there are significant differences in functional characteristics between fish source MPs and mammalian MPs,and the functional characteristics of fish MPs are poor.As a simple and efficient treatment method,ultrasound has been widely used in the study of biological macromolecule modification.Therefore,it is important to modify fish MPs with ultrasonic waves.It is of great significance for the development of fish and meat products and the application of ultrasonic wave technology in meat processing to clarify the difference between fish(commercial surimi)MPs and mammalian MPs,study the effect of ultrasonic treatment on the improvement of physical and chemical properties and functional characteristics of fish MPs,and explore the regulatory mechanism of ultrasonic modification on the functional characteristics of fish MPs.The main research contents and conclusions of this experiment include:1.To compare the physical and chemical properties and functional characteristics of fish MPs and mammalian MPs(cattle,sheep and pig).The results showed that the protein/fat content of fish was 9.90,which was significantly higher than that of mammalian meat(p < 0.05),1.33 times that of beef,2 times that of mutton and 1.48 times that of pork;The molecular weight distribution showed that the myosin heavy chain(MHC),myosin light chain(MLC)and actin content of fish MPs were lower than those of mammalian MPs;The functional properties of fish MPs,such as solubility,foaming,emulsifying and gelling,were significantly lower than those of mammalian MPs(p < 0.05).2.Based on the physicochemical properties and protein structure of fish MPs after ultrasonic treatment,the internal mechanism of ultrasonic-modified MPs was studied.The results showed that ultrasonic treatment induced the depolymerization of fish MPs,the unfolding of protein high-order structure and the formation of disordered structure,significantly increased its fluidity and structural rigidity,and improved its shear resistance.In addition,the particle size and viscosity of fish MPs decreased with the extension of ultrasonic treatment time,while the free sulfhydryl content and surface hydrophobicity increased with the extension of ultrasonic treatment time.3.Explore the effect of improving the functional characteristics of fish MPs after ultrasonic treatment.The results showed that the solubility of fish MPs was 97.44% after ultrasonic treatment for 10 min,which was 1.58 times higher than that of untreated MPs(p< 0.05);Foaming,emulsifying and gelling properties were significantly enhanced(p < 0.05).Further study on the stability of MP-soybean oil emulsions showed that after ultrasonic treatment for 10 min,the content of adsorped interfacial proteins in modified emulsion was significantly increased,while the droplet size of emulsion was significantly decreased.The emulsion fluidity was significantly improved after modified by ultrasonic treatment(p <0.05).