[en] Abstract: A study was carried out to evaluate the performances of colored spirulina (Spirulina platensis)
soluble proteins fractions as surfactants at water/n-dodecane interface using a drop volume tensiometer. Also the
mechanical behavior at this interface were studied via an automated drop tensiometer. Various concentrations
(0.1%; 0.3% and 0.5% (w/w)) and pH levels (native, 3 and 5) were tested. Results showed that the interfacial
tension decay increased with increased protein concentration. Also, at 0.3% (w/w) colored protein in
the aqueous phase there were no significant difference in interfacial tension decay between the native pH and the
pH3 levels while at pH5 the surface tension decay was greater. The viscoelastic moduli and the equilibrium
interfacial tension of the fractions suspensions also decreased with concentration.
