Study On The Composition And Characteristics Of Giant Salamander Muscle Protein

The giant salamander is an amphibian and reptile,which has rich nutrition,protein and amino acid.With the increasing number of cultured giant salamander,it has begun to be processed and utilized,but the composition and characteristics of giant salamander muscle protein are still unclear.Based on the giant salamander muscle,the muscle composition,amino acid content,elemental composition,and muscle tissue changes of different freezing methods were analyzed.The sarcoplasmic protein,myofibrillar protein and muscle myomatrix protein were isolated and their properties were determined.The main findings are as follow:?1?The nutritional components of giant salamander muscle and characteristics of isolated protein.The water,protein and essential amino acid content were 79.52%,17.08%and 47.30%,respectively.There are many elements,among which calcium,iron,zinc,and selenium were more abundant.There were sarcoplasmic protein,myofibrillar protein and muscle matrix protein in giant salamander muscle,the contents of which were 4.91%,9.03%and 2.28%respectively.Sarcoplasmic protein was distributed in the range of 20-200 kDa,myofibrillar protein mainly includes 200 kDa myosin heavy chain,43 kDa actin and 36 kDa myosin,muscle matrix protein was distributed in the range of 29-40 kDa,160-200 kDa.The maximum UV absorption peaks of three proteins were all at 280 nm,there were infrared characteristic absorption peaks of myofibrillar protein in amide A,B,I,?and?bands,while the infrared characteristic absorption peaks of sarcoplasmic protein and muscle matrix protein only appeared in amide I,?and?bands.The surface of sarcoplasmin protein was smooth,myofibrillar protein was a rod-shaped or granular polymer,and muscle matrix protein had a more complete fiber structure.?2?Functional characteristics of sarcoplasmic protein.Sarcoplasmic protein was non-sticky and could not form a gel alone.Its solubility,foamability,and foam stability decrease with increasing temperature.Turbidity,emulsification activity,and emulsification stability increased with increasing temperature,and the protein denaturation at 60?;At pH6.0,the solubility of sarcoplasmic protein was the lowest,and turbidity increased first and then decreased with the increasing pH.The emulsifying activity and emulsion stability were the best at pH 9.0,the foaming ability was the best at pH 12.0,and the foam stability was best at pH 11.0;Vitamin C and citric acid could reduce the solubility of protein,oat?-glucan could increase the solubility and foaming of protein,sodium alginate could improve the emulsifying activity and foaming of protein,but had little effect on the solubility of protein;When the pressure was 200 MPa,the sarcoplasmic protein had the highest solubility,the emulsification stability,foaming property and foam stability at 300 MPa were the highest,and the emulsification activity was the highest at 400 MPa.?3?Functional characteristics of myofibrillin protein.The solubility,emulsifying activity and stability,foaming and foam stability of myofibrillar protein decreased with the increase of temperature.Turbidity increased with the increase of temperature,and the protein denaturation at 50?;With the increase of pH,the solubility of myofibrillar protein decreases,the solubility was the lowest at pH 5.0,and the turbidity showed a trend of first decline and then increase.The emulsification activity and emulsification stability were highest at pH 11.0,and the foaming property was highest at pH 9.0,Foam stability was highest at pH 8.0;Vitamin C,citric acid and gallic acid could reduce the solubility,viscosity,foaming,foam stability of protein,and increase protein turbidity,gel hardness,chewiness.Citric acid could reduce the emulsifying activity of protein,while vitamin C,gallic acid and sodium glutamate could increase the emulsifying activity of protein.Sodium alginate and oat?-glucan could improve protein emulsifying activity,gel retention and cohesion,but had little effect on protein solubility;100 MPa protein viscosity increased,200 MPa protein foaming and foam stability,gel water retention,hardness and chewiness were highest,300 MPa gel elasticity and cohesiveness were good,400 MPa solubility and emulsification activity was better.?4?Sensory and Physicochemical Properties of Collagen protein in muscle matrix proteins.Using acetic acid,pepsin and trypsin to extract the collagen protein in muscle matrix protein,the extraction rate of acetic acid method,stomach enzyme method and pancreatin method were 6.91%,18.59%and 12.38%,the content of hydroxyproline was 10.49%?8.67%?and 5.26%respectively;The UV absorption peaks of the three kinds of collagen were all at232nm,and there were characteristic absorption peaks of amide A,B,I,?and?bands in the infrared spectrum,which were consistent with the characteristic absorption peaks of collagen protein;The collagens produced by the acid method and stomach enzymatic method both contain two kinds of?peptide chains??₁ and?₂?and a?peptide chain,which was typical type I collagens and was consistent with the collagen type of giant salamander skin;Acid extraction is beneficial to maintain the collagen protein network structure,enzymatic method could decompose collagen protein protease into small molecule collagen peptides.