Preparation And Function Activity Of Silkworm Peptide

The protein is macro-molecule with the spatial structure which was joined mutually by different kindsof amino acid. The biological physics and chemistry characteristics (molecular weight, amino acidcomposition, and so on) and the function characteristics have directly relationship. The proteinmodification is that changes in the protein macro-molecule spatial structure and the physics and chemistrycharacteristics are caused by some changes of the amino acid and the multi-peptides chain because of thebiochemistry factor or the physical factor.The peptide is formed by more than two amino acid member jointing, it is the structure fragmentconstituting the protein, also is active gene position of protein function. The peptide is also related directlywith the immunity function, and is the important active material of the immunity function and the immunityadjustment in body. The biological activity peptide is the peptides that can adjust the vital activity in thebiological organism or have certain biological activity functions. These biological activity peptides areexisted mostly as the non-active state in the long protein chains, only when they are dissolved by enzyme tothe suitable length, their biological activity can display.The silkworm pupa is a stage of life cYcle in Antherea pernyi Guerin-Meneville. The protein andpeptide from silkworm pupa (silkworm of) contains more than 60% of the essential amino acids in ourbody and also have variety of other nutrients. It can be utilized as a functional ingredient to improve humanhealth such as anti-weary, anti-old, improving immunity in body etc. Extracting the protein from silkwormpupa was studied using supercritical CO₂ method to extract silkworm oil in this research. The optimumtechnology of extracting the protein and hydrolyzing by enzyme in silkworm pupa protein were obtained.Meanwhile separation and refining and the function activity of silkworm pupa protein peptide were studiedin this research.The silkworm pupa powder was prepared, and the silkworm pupa was defatted by the supercritical CO₂method. The parameters in supercritical CO₂ extraction were studied. The orthogonal(L₉(3⁴)) designadopted to choose the optimum technological conditions of supercritical CO₂ extraction. The parameterswere: extraction temperature: 45℃, pressure: 25MPa and time: 180min. The extraction rate was 95.99%.Scalping of enzymes was operated firstly during the process of hydrolysis. The 2709 alkaline wasoptimum, it was determined under the optimum condition of the enzymes using the DH (degree hydrolysis)as the index. The effects of pH value, time, temperature, solid-liquid ratio and enzyme amount to thehydrolysis of silkworm pupa peptide were observed. On the basis of single factor, the optimum hydrolyzingcondition was determined by the orthogonal (L₁₆(4⁵)) design, temperature: 55℃, pH: 9.0, solid/liquid: ratio 1/7, enzyme concentration: 7ï¼…, time: 2.5h, and the degree of hydrolysis could achieved 29.97ï¼….During the process of hydrolyzing by enzyme, acid and alkaline were added to keep the optimum pH,lots of salt were produced and the color of protein peptide was dark. Therefore the protein peptide neededto be refined. The peptide in silkworm pupa was clear and had good taste by adding 3ï¼…activated carbon.91.20ï¼…of salt could be eliminated through the masculine and feminine elements ion exchange resin. Therefined silkworm pupa peptide was obtained.The physics and chemistry characteristics of the refined silkworm pupa peptide were studied. Theeluting curve of hydrolyzed liquid in silkworm pupa peptide was a sole symmetrical peak by thetechnology of filtering and separating of gel. This indicated that the purity of hydrolyzed liquid was highly,the molecular weight was well-distributed. The molecular weight distribution was determined by theSDS-PAGE method. The molecular weight of silkworm pupa peptide was about 3,000 Dalton.In addition, the silkworm pupa peptide had the active function of anti-fatigue by animal experiment.The silkworm pupa peptide had the profound significance as the function healthy products.