Study On The Modification And Application Of Wheat Gluten By Ultra High Pressure

Wheat gluten protein is a kind of traditional food additive and quality improving agent,but its functional properties have some defects.To improve the functional properties of gluten has important theoretical and practical significance.In this thesis,the effect of ultra high pressure treatment on the functional,nutritional and structural properties of wheat gluten were studied.The main results were as follows:(1)The gluten protein was extracted from Zhoumai 18 wheat flour using a Martin method,and gliadin and glutenin was separated from obtained gluten.The protein content of the protein was 83.6%,the moisture content was 10.6%,and the content of starch and ash was also contained.(2)After 200 MPa high pressure treatment,the water absorption decreased but was not significantly changed after treatment with 400 MPa and 600 MPa.The water absorption of gliadin increased with pressure increase,the water absorption of glutenin decreased after 200 MPa and 400 MPa treatment,but increased after the treatment of 600 MPa,reaching 2.01mL/g.The solubility of gluten and gliadin decreased with the increase of pressure,the solubility of glutenin increased with pressure increase.(3)The oil absorption of gluten and gliadin did not change significantly with the increase of the pressure.The oil absorption of glutenin with 200MPa treatment decreaced,comparing to the control group,those with 400,600MPa treatment had no significant change.Gliadin and gluten protein after 200-400MPa treatment,foaming ability has been improved,but foaming ability decreased with 600MPa treatment.The foaming ability of glutenin increased with pressure increase.Foaming stability of gluten decreased with the pressure increase,the foaming stability of gliadin and glutenin without significant changes.(4)The emulsification of gluten increased firstly with pressure increase and then decreased,reach minimum 11.04m2/g after 600MPa treatment.The emulsification of gliadin decreased with pressure increase,the emulsification of glutenin decreased firstly with pressure increase and then increased,reached maximum 13.60m2/g after 600MPa treatment.Emulsion stability of gliadin and gluten protein increased with pressure increase and emulsification stability of glutenin increased firstly with pressure increase and then decreased.(5)Ultra-high pressure had no obvious effect on gliadin protein SH-content,but reduced the SH-content of gluten protein and glutenin,then the disulfide bond content increased.SDS-PAGE,FTIR and Raman spectra show that the 0.1-600MPa pressure is not enough to cause damage to the primary structure of the protein,but the secondary structure of the protein is significantly affected.DSC results showed that the To(onset temperature)of gluten decreased firstly with the pressure increase,and then increased.The 600MPa was higher than that of the control group.To of gliadin decreased with pressure increase.To of glutenin increased with 200MPa treatment,no significant change in those of the control group,400 and 600MPa treatment.Ultra-high pressure could increase the glass transition temperature Tg of gluten and gliadin,but decreased the Tg of glutenin.Scanning electron microscope results showed that the gluten protein texture had no significant effect with ultra-high pressure,but the texture of gliadin and glutenin was affected.Pressure broke the gliadin subunit spherical structure down.