Extraction Of Wheat Germ Protein And The Effect Of Ultra-High Pressure To WGP Functional Property

Wheat germ is one of the main byproduct of wheat-milling industry. It is a rich source of protein, the content of protein is 30%. Which make wheat germ one of attractive and promising source of protein. For increasing the rate of extraction of wheat germ and improving it's properties, in this research, extraction of wheat germ protein (WGP) from wheat germ was studied, and the series process of WGP was optimized by test. Then the effect of WGP function and character on ultra-high pressure was studied.At first, the process of wheat germ degreasing with supercritical CO₂ were optimized by orthogonal test. Then the best technical parameters of WGP extracted with alkali dissolve and acid deposition were confirmed. At last, the effect of ultra-high pressure to WGP properties were studied, the properties including WGP solubility, emulsion activity, emulsion stability and surface hydrophobicity, and analyze the relations among functional properties. The main result as follow:1,The optimal wheat germ degreasing with supercritical CO₂ were that the extraction pressure was30MPa, the extraction temperature was 50℃, and the separation time was 2 hour.2,The optimal parameters of WGP extraction were that the pH was 10, the hydrolyzing time was 60 min; the temperature was 45℃, and the ratio of material and water was 1:16.3,The solubility of WGP was increased with ultra-high pressure effect. The emulsion activity, emulsion stability and surface hydrophobicity of WGP were reduced with prolong use of ultra-high pressure. It demonstrated showed that ultra-high pressure has a remarkable effect on protein folding, the hydrophobic regions were moved from surface of the molecule to inside by ultra-high pressure effect. Surface hydrophobicity was unconspicuously improved with WGP concentration increased. The molecular mass was determined by SDS-PAGE electrophoresis as follows: 55.7Kda, 44.41 Kda, 40.7 Kda, 23.7 Kda, 20.41 KDa and some 18.14～12.41KDa ones, the result indicated that the primary structure of WGP was not changed by ultrasonic and ultra-high pressure. The research of ultra-high pressure technology of WGP must provide helpful and reference on making the best use WGP。...