Gelation of edible blue-green algae protein isolate (Spirulina platensis Strain Pacifica): thermal transitions, rheological properties, and molecular forces involved.

摘要: Proteins isolated from blue-green algae Spirulina platensis strain Pacifica were characterized by visible absorption, differential scanning calorimetry (DSC), viscometry, and dynamic oscillatory rheological measurements. Unique thermal unfolding, denaturation, aggregation, gelation of the algal protein isolate are presented. DSC analysis showed that transitions occur at about 67 109 degrees C neutral pH. Calcium chloride stabilized quaternary structure against denaturation shifted higher temperatures. Viscometric studies as a function temperature onset viscosity increase is closely related to dissociation-denaturation process. Lower viscosities observed for solutions dissolved pH 9 due an increased solubility. Solutions form elastic gels during heating 90 C. Subsequent cooling ambient temperatures caused further pronounced in moduli network elasticity. has good gelling properties with fairly low minimum critical concentrations 1.5 2.5 wt % 0.1 M Tris buffer, 7, 0.02 CaCl(2) same respectively. It suggested mainly interactions exposed hydrophobic regions generate molecular association, initial treatment. Hydrogen bonds reinforce rigidity on stabilize but alone not sufficient structure. Intermolecular sulfhydryl disulfide found play minor role strength affect elasticity structures formed. Both time isothermal heat-induced within 40-80 substantially formation development modulus gels. This also attributed strong dependence interactions. The likely be controlled protein-protein complexes rather than individual molecules.