摘要
研究了不同的pH值、溶剂系统、增塑剂和盐类对大豆蛋白膜(ISPF)的机械性质(抗张强度TS和延伸率E)和水蒸气渗透性(WVP)的影响.研究表明,当pH=4时,ISPF的机械性质最差,pH9时ISPF的TS值最高(6 8MPa),pH=11时E值最高(238%),而pH=9时的WVP值最低(0 82ng·m/m2·s·Pa).随着加入的增塑剂中甘油(GLY)/聚乙二醇(PEG)的比值的增加,ISPF的机械性质降低,WVP值也降低.当溶剂系统中乙醇浓度逐渐增加时,所制备的ISPF的机械性质和WVP值均有所下降.当蛋白质溶液中加入KCl和MgCl2时,可降低ISPF的机械性质,提高其WVP值.加入CaCl2时,ISPF的机械性质降低,WVP值也降低.
Isolated soy protein films (ISPF) are prepared from isolated soy protein at curious pH,with different plastizers,curious mixture rations of water and ethanol,and with various concentrations of different salts,and tensile strength(TS),the elongations(E) and the water vapro permeabilities(WVP) of these films are determined.The mechanical properties of ISPF prepared at pH4 are worst among the films,TS of ISPF prepared at pH9 is 6.8 MPa which is the highest among the films,the E of the films prepared at pH11 is 238% which is the highest,and WVP of the films prepared at pH9 is the lowest(0.82 ng·m/m^2·s·Pa)among the films.TS,E and WVP decreased as the ethnol/water ratio increased.The mechanical properties of increased.TS,E and WVP also decreased as the glycerin(GLY)/polyethylene golycol(PEG) ratio increased.TS,E and WVP also decreased as the ethnol/water ratio increased.The mechanical properties of ISPFs containing potassium chloride and magnesium chloride are lower than those without the salts,while WVP is higher.But the mechanical properties and WVP of ISPFs decreased when calcium chloride added in them.
