Broad Bean Protein Extraction, Functional Properties And Enzymatic Studies

In this thesis it determined the protein content of the20varieties of broad bean in themain producing areas of China, studied the characteristics of water-soluble, salt-soluble,alcohol-soluble, established water extraction process of broad bean protein, discussed thefunctional properties of solubility and gelation properties of broad beans protein,investigated the components of molecular weight distribution of soluble-soluble andsalt-soluble protein by SDS-PAGE method, limited hydrolyzed broad bean protein withtrypsin, measured the impact of broad bean protein on ham textural characteristics. Theresults showed that:20kinds of main producing areas of broad bean protein content rangedfrom26.48%to32.51%, the content existed significant differences (significant coefficient p<0.05); according to solubility characteristics of broad bean protein, it could be divided intowater-soluble protein, salt-soluble proteins, alcohol-soluble protein and alkali-solubleprotein. Their contents were90.79%5.84%,0.28%,0.18%of the total protein, in addition,it contained about2.91%of the non-protein nitrogen; Broad bean protein had a highersolubility in water under the condition of solid-liquid ratio of1:10, room tempreture,thedistilled water extract broad protein for1time, the protein extraction rate was78.62%,Thetotal extraction rate was92.65%when extracted it three times; Broad bean protein’sisoelectric point was pH4.0, In the aqueous phase, the protein could form a gel afterheating and cooling in a certain concentration, the minimum concentration for protein toform a gel was14%. When the pH of the aqueous phase was4.0-6.0, Protein gel could notformed. NaCl and CaCl2affected both broad bean protein gel, NaCl concentration was0.05M, broad bean protein gel’s strength was the highest, and concentration of CaCl2was0.005M, broad bean protein gel’s strength was the highest. The broad bean water-solubleprotein and salt soluble protein isolated10-19and7-16electrophoretic bands whichconcentrated between of43.0-95.0ku and20-65ku, respectively.The number of20kinds ofbroad bean protein electrophoresis bands were different because of the different varieties.Trypsin could hydrolyzed broad bean protein, it could hydrolyze the broad bean in control.By controlling hydrolysis time, broad protein were limited hydrolyzed to obtain a degree ofhydrolysis of1.0%,2.5%and5.0%of the polypeptide, its solubility improved than theformal protein, while its gelation reduced. Adding a certain amount of protein to the ham,its hardness, adhesiveness, elasticity and chewiness were significantly affected. Adding onepercent of the amount of broad bean protein to ham could make its texture and sensoryevaluation optimal.