Interaction Between Modified Soy Protein And Fish Myofibrillar Protein And Its Composite Gel Properties

Consumers' processing of meat depends on the quality of the product,the quality of the flavor,the texture and the stability of the storage.The common practice in processing meat products is to add protein ingredients to the product formula,the main purpose is to improve the physical properties(especially Texture-related properties),flavor and cooking yield,and reduced production costs.In recent years,due to the improvement of people's living standards,low-fat and low-salt products have received widespread attention,and consumers' demand for low-fat products has increased.Use non-proteinaceous substances as an additive to reduce fat intake.In actual meat processing,the use of non-meat proteins such as soy protein,whey protein and pea protein can significantly improve texture-related characteristics,flavor and retort.To improve the nutritional and functional properties of meat and meat products,soy protein isolate(SPI)has been widely used as a non-meat protein addition in the meat processing industry.Some studies have reported that natural soy protein isolate(N-SPI)has a bad influence on the gel properties of meat proteins.This is due to the poor interaction between soy protein and meat protein.Therefore,it is necessary to change the natural structure of soy protein.In this paper,the soy protein was modified by heating,polar pH treatment and mild pH after mild heat treatment to study the structural properties of modified soy protein isolate.The interaction between the heat-modified soy protein isolate and the fish myofibrillar protein hybrid gel was investigated.To study the interaction between acid treatment and polar mild heat treatment and fish myofibrillar protein,and discuss what kind of processed soy protein isolate is beneficial to the gel properties of fish protein,which can be applied to actual processing and production.The rational application of soy protein isolate in fish products improves the quality of fish products.In this study,the effects of heat induction on the structure of soy protein isolate were investigated by studying the solubility,surface hydrophobicity and sulfhydryl content of soy protein isolates at 60 ° C,80 ° C and 95 ° C.The results showed that the solubility increased with the increase of heat-induced SPI temperature;the surface hydrophobicity and sulfhydryl content increased with the increase of heat-induced SPI temperature,indicating that the heating caused the hydrophobic group and the internal SH group to be exposed,which changed the soy protein isolate.The structure,which increases the surface hydrophobicity and sulfhydryl content,is significantly lower than SPI 80 °C(P < 0.05)due to excessive temperature,causing aggregation of protein subunits.From the rheological curve,the rheological curve of soy protein isolate is basically linear,but the G' of SPI 80 °C is significantly higher than other control groups,indicating that the heat induced 80 °C caused the change of ?-conglycinin(7S)structure..According to the SDS-PAGE electrophoresis map,all SPI bands have ?,?',?,acidic peptide A and basic peptide B.After heat treatment,the SPI bands become shallow.In summary,SPI80°C will Produce ideal structural changes.Secondly,the soy protein isolate(SPI)was treated at 60 °C,80 °C and 95 °C,and then added to the fish myofibrillar protein(MP)to study the interaction between fish myofibrillar protein and heat-induced soy protein isolate.The effect of the properties of the glue.The results showed that compared with the natural soy protein isolate gel(MP-N-SPI),the storage modulus(G')(P < 0.05)of MP-SPI(80 ° C)increased significantly,while MP-SPI(60 ° C)and MP-SPI(95 ° C)storage modulus is lower than MP-N-SPI.After adding SPI to MP,the water holding capacity of the composite gel was higher than that of MP alone.The suitable heat-induced temperature SPI(80 °C)could significantly improve the water holding capacity(WHC)of the protein composite gel(P < 0.05).It can be seen from the texture characteristics that the hardness of MP-SPI(95 ° C)is significantly improved.The SDS-PAGE of the supernatant after centrifugation of the composite gel showed that the MP-N-SPI composite gel strip was not significantly different from the MP alone,MP-SPI(80 ° C)and MP-SPI(95 ° C)strips.The band is lighter than MP-N-SPI and MP-SPI(60 ° C),indicating that pre-heated SPI(80 ° C or 95 ° C)is easy to interact with myofibrillar proteins.The results of chemical force measurement showed that the gel network of preheated soy protein and MP formed mainly as a result of hydrophobic interaction,and hydrogen bond and disulfide bond were not the main chemical forces formed by the composite gel.In general,a suitable heat-induced soy protein isolate can significantly improve the properties of the composite gel,provide great potential for the development of soy protein,and achieve a balance between animal and plant proteins.This experiment explored the effect of polar pH treatment SPI on the gel properties of myofibrillar protein,and analyzed it from rheological,water-holding,texture and chemical properties.The results show that from the rheological properties,the pole The storage modulus of the soy protein isolate gel was higher than that of the pH offset combined with the heat treatment composite gel.The storage modulus of SPI treated with pH 1.5 was higher than that of pH 12 treatment,and the complex protein appeared.The same result is due to the fact that the reactive side chain groups in the SPI treated at pH 1.5 promoted the interaction of the MP and SPI proteins,resulting in a stronger and more elastic final gel structure.From the perspective of texture characteristics,the hardness and chewiness of the modified soy protein isolate composite gel are higher than that of MP-N-SPI,and the water holding capacity is higher than that of the natural soy protein composite gel,indicating that the modified soy protein isolate is exposed.More groups.Conducive to hydrophobic interactions.From the analysis of chemical results,hydrophobic interaction is the main force for gel formation.Hydrogen bonds and disulfide bonds are not the main chemical forces involved in the gel.From the SDS-PAGE electrophoresis analysis,the structure of 7S decreased or disappeared,and the structure of 11 s decreased,indicating that the 7S structure in SPI was changed after pH shift treatment.However,after mild warming by pH shift,the bands showed a deepening and the bands became scattered.The combination of pH 12 and mild heat treatment is not conducive to the formation of the composite gel,which is consistent with the previous rheological and texture properties.