Dissertation > Excellent graduate degree dissertation topics show

Study on the Emusifying Properties of Soy Protein-Polysaccharide Complexes

Author: XuZuoZuo
Tutor: YaoPing
School: Fudan University
Course: Polymer Chemistry and Physics
Keywords: soy protein dextran ultrasound emulsification covalent conjugate emulsion stability
CLC: TS201.21
Type: Master's thesis
Year: 2009
Downloads: 468
Quote: 1
Read: Download Dissertation

Abstract


Proteins have been used as emulsifiers in food products for many years.The stability of protein contained oil-in-water emulsions depends strongly on the density and structure of the protein adsorption layers on drop surface.The protein adsorption layers prevent the drop-drop coalescence by stabilizing the emulsion films.However,protein-stabilized emulsions are highly sensitive to environmental stresses such as pH,ionic strength and temperature.When the pH approaches the isoelectric point of protein and/or salt concentration is higher in emulsion,the electrostatic repulsion of the protein adsorption layers decreases and therefore coalescence and creaming happen.When emulsion is subjected to heat treatment,for pasteurization or sterilization purposes,aggregation happens because of the denaturation of protein which holds the droplets together.Proteins of plant origin do not function effectively at acidic pH environments since they precipitate at pH values close to their isoelectric point.Most foods and beverages are acidic. Therefore,the poor emulsion stability at isoelectric point limits protein application in food and beverage industries.Among proteins of vegetable origin,soy protein is an abundant byproduct of soybean-oil industry and has good functional properties for food processing because of the high nutritional value and the contribution to food texture and emulsifying properties.However,to the best of our knowledge,the long-term stable emulsions stabilized by soy protein at acidic conditions have not been reported.This thesis studied the emulsifying properties of acid soluble soy protein(ASSP)-dextran conjugates at neutral pH.Two natural biomacromolecules,ASSP and dextran,are used to prepare the conjugates through the Amadori rearrangement of the Maillard reaction.The effects of the reaction time with different weight ratios of ASSP to dextran(WR) were investigated and the resultant conjugates were characterized by SDS-PAGE,turbidity,and light scattering.The conjugates can greatly improve the solubility/dispersibility of ASSP in the pH range of 4-6.Ultrasound emulsification was used to prepare emulsions.The effects of environmental stresses,such as pH,ionic strength,heating and storage,were investigated by light scattering.The emulsions prepared from WR 1:9 conjugate having submicron droplets are stable against heat treatment,long-term storage,the changes of pH and ionic strength.The emulsions were characterized withζ-potential and atomic force microscope. The bulky hydrophilic chains of dextran on the droplet surface greatly decrease the movement of the droplets as they were subjected to the electric field,which leads to the reduction of theζ-potentials.AFM result reveals that the ultrasonication can destroy the original aggregates in the conjugate solution and induces the formation of new aggregates. In the ultrasonication process,the increases of surface activity and aggregation of protein result in a formation of stable oil-water interface films.It was further verified that using protein-polysaccharide conjugates and ultrasonication emulsification is a versatile method for preparing stable emulsions.We also investigated the emulsification capability and stability of WR 1:9 conjugate at acidic pH.Compared with the emulsifying at neutral pH,the conjugate exhibits poorer emulsification stability.The reason is unknown at this stage.

Related Dissertations

  1. Recovery Whey Soy Protein by Microfiltration and Development of Whey Powder,TQ936.2
  2. The Research on the Comprehensive Modification Technology of Rice Protein Enzymatichydrolysis and Graft Copolymerization,TS201.2
  3. Roles of MMP-7 and Lysozyme in the Pathogenesis of Ulcerative Colitis Induced by DSS in Balb/c Mice,S858.91
  4. Separation and Enrichment of Heavy Metals and Biological Materials by the Technique of Emulsion Liquid Membrane,TQ028.8
  5. Study on Formaldehyde-free Straw Board Bonding with Soy Protein Adhesive,TS653.6
  6. Study on the Technology of Poplar Plywood and LVL with PF Resin or Soybean Adhesive,TS653
  7. Study on Co-gel of Soybean Protein Isolate and Salt-soluble Meat Protein,TS201.21
  8. The Influences of Storage Conditions on Functionalities of SPI,TS201.2
  9. Studies on the Preparation and Application of High-emulsifying Soybean Protein,TS201.2
  10. The Effect of Sanguis Draxonic to Rat of DSS-induced Ulcerative Colitis on the Activated Platelets,R285.5
  11. The Effect of Different Contents of Soy Protein in Diet on Uric Acid and Renal Function in Hyperuricemic Rats,R-332
  12. Preparations of Wood Adhesives Using Soybean Protein,TQ437
  13. The Research for the Operation Characteristics and the Processing Performance of Anaerobic Baffled Reactor (ABR) Treating Soybean Wastewater,X703
  14. Anaerobic Baffled Reactor Treating Two Kinds of Food Wastewater of Start-up and Operation,X703
  15. Quantum dot as a probe resonance Rayleigh scattering method in the analysis of the application of polysaccharide,O657.3
  16. Studies on the Construction of Protease Engineering Strains and Modification of SPI Applied to the Pork Sausage,TS201.21
  17. The Critical Technology of Enzymatic Succinylation Modification on Soybean Protein Isolated and the Application Research on the Chiffon Cake,TS213.23
  18. Highly functional soy protein / polyester fabric Preparation,TS106
  19. Antibacterial enzyme modified soy protein isolate membrane preparation and properties of,TS201.2
  20. The Protective Effects of Perfluorocarbon on the Injury of Pulmonary Alveolar Epithelial Cells Induced by Ischaemia-reperfusion Injury and the Investigation of Probable Mechanism,R363
  21. Synthesis and Characterization of Dextran-based Dual Stimuli-responsive Nanogels,O648.17

CLC: > Industrial Technology > Light industry,handicrafts > Food Industry > General issues > Basic science > Food Chemistry > Protein
© 2012 www.DissertationTopic.Net  Mobile