High Pressure Effects On Biomacromolecules

In recent years high pressure technology has received considerable attention as a method of td processing and preservation. High pressure influences the conformation of biomacromolecules, alters the non-covalent interaction among macromolecules, changes their physiochemical and functional properties. Research on this area is state- of- the- art of high pressure technology.The traditional oriental food soybean milk has been studied by multiple analysis ways. The effects of high pressure on the physiochemical properties of soybean milk and conformation change of soybean protein in soybean milk have been analyzed, the relationship between them has been clarified; Physical properties and microstructures of high pressure induced Tofu gel are studied; Fractal analysis is applied to find the relationship between box dimension and the physical properties of Tofu gel; The mechanism of high pressure induced Tofu gel is discussed; High pressure effects on physical properties of isolated soybean protein{ISP} has been elucidated, the different characteristics of high pressure induced gel are compared with heat induced gel ; and also the mechanism of high pressure induced ISP gel is discussed. The high pressure effects on the structure properties of glycinin and P -conglycinin are analyzed and the mechanism of high pressure denaturation protein is clarified; By simulating the real food systems, high pressure effects on the interaction of protein and polysaccharide are studied; The relationship between the change of protein structure and function are studied in the presence of polysaccharide.High pressure is applied to soybean milk and the physiochemical properties of soybean milk and conformation change of soybean protein are examined. Its viscosity increases when the pressure increases, but its pH value and density have no apparent change. When the pressure is lower than 400Mpa, the soybean milk keeps liquid; However, the soybean milk changes from a liquid to a sd after treatment at 500MPa for 30mm.The liquid soybean milk shows improved emulsifying activity and stability but reduced emulsifying capacity after processed by high pressure; Sulfhydryl content of the soybean milk saturated with N2 is increased slightly after high pressure processing; Fluorescence analysis reveals that soybean protein are modified by high pressure to have larger hydrophobic regions. The change of physical properties of soybean milk is related to the conformation change of soybean protein in soybean milk.The denaturation pressure of glycinin and P -conglycinin are first reported by differential scanning calorimetry analysis; P -conglycinin can be denatured completely by 300MPa,l0min and 400MPa,5min for glycinin at room temperature; Native-PAGE electrophoresis revealed that soybean proteins are dissociated and some of them coagulated by high pressure.; The effective sterilization of soybean milk is observed after processed by 400MPa for 10mm; After pressure treatment soybean milk shows a higher affinity for saponins which will lead to change the flavour of soybean milk.The strength of high pressure induced Tofu gel is related with coagulant, pressure and time; High pressure induced Tofu gel has smooth appearance; Scanning electron microscopic examinations as well as gel strength measurements reveal that when the network structure of Tofu gel is homogeneous, the strength is higher; The mechanism of high pressure induced Tofu gel may be caused by the denaturation of protein; and with the synergistic reaction of coagulant, the gel6network is formed although the protein concentration is low.Fractal theory is applied to physical properties analysis of Tofu gel in a creative way; It isfound that the box dimension of Tofu gel can represent its microstructure characteristic. The boxdimension of Tofu gel is positive correlation with its gel strength.Both pressure and heat induce the gel formation of ISP The geI strength of lSP is increasedwitIl its concentration, and tightly connected with pressure and. Temperature...