RELATIONSHIP BETWEEN INTERFACIAL AND FOAMING PROPERTIES OF SOY PROTEIN ISOLATE AND THEIR HYDROLYSATES WITH POLYSACCHARIDES

MARTINEZ, K. D.; CARRERA SÁNCHEZ, CECILIO; RODRÍGUEZ PATINO, JUAN M.; PILOSOF, ANA M.R.

Ambato, Ecuador

Congreso; VI Congreso Iberoamericano de Ingeniería de Alimentos (CIBIA VI); 2007

Facultad de Ciencia e Ingeniería de Alimentos, Universidad Técnica de Ambato

SUMMARY The objective of the work was to study the relation between foaming and interfacial properties of soy protein and their hydrolysates with polysaccharides at 2%/0.25% wt% respectively. As starting material a sample of commercial soy protein isolate was used (SP) and hydrolysates were produced by an enzymatic reaction. In this contribution we are concerned with the analysis of foaming by whipping method (foam overrun (FO), stability against liquid drainage (Kdr) and collapse (collapse time 10ml)) and interfacial properties (surface dilatacional rheology). The effect of polysaccharides on foaming properties depended in a complicated way on the degree of hydrolysis of soy protein and the kind of polysaccharide, being foam stability the consequence of the contribution of polysaccharide to bulk viscosity and to film elasticiy/viscoelasticity. Relative viscoelasticity of films from the less hydrolyzed soy protein increased in the presence of polysaccharides, but decreased or did not change for the more hydrolyzed protein. This points out that a limited hydrolysis is sufficient to improve the properties of surface films when the protein is used in combination with polysaccharides.