Rheological properties of patatin gels compared with β-lactoglobulin, ovalbumin, and glycinin

BACKGROUND: The thermal unfolding and rheological properties of patatin gels were compared with those of commonly used proteins (beta-lactoglobulin, ovalbumin, glycinin). RESULTS: A significant difference between these proteins was observed in both the denaturation temperature (59 degrees C for patatin; about 20 degrees C lower than the other proteins) and the onset temperature of gel formation (50-60 degrees C, compared to 70-85 degrees C for the other proteins). At low ionic strength the minimal concentration was only 6%(w/v) for patatin, compared to 8-11% for the other proteins. This effect was attributed to the relatively high exposed hydrophobicity of patatin as determined by hydrophobic interaction chromatography. For gels compared at 'iso-strength', the frequency dependence was found to be close to identical, while small differences were observed in the strain at fracture. CONCLUSIONS: Patatin was found to form gels with comparable small-deformational rheological properties as typical food proteins. In addition, at concentrations where the elastic modulus was similar for all proteins, the frequency and strain dependence were also comparable. From this it is concluded that patatin is a promising protein to be used in food applications as a gelling agent. (C) 2010 Society of Chemical Industry