AGGREGATION AND GELATION PROPERTIES OF EGG WHITE PROTEINS, AS AFFECTED BY HIGH INTENSITY ULTRASOUND

ARZENI, CAROLINA; PÉREZ, OSCAR E.; PILOSOF, ANA MR.

Atenas

Congreso; 11th International Congress on Engineering and Food; 2011

International Association for Engineering and Food IAEF

The goal of this contribution was to determine the impact of HIUS on the thermal aggregation and gelation of EW proteins.EW solutions were sonicated for 20 min using an ultrasonic processor Vibra Cell Sonics, model VCX 750 (frequency: 20 kHz; amplitude: 20%). The particles size distribution was measured by light scattering using a Mastersizer 2000 with a Hydro 2000MU dispersion unit from Malvern Instruments Ltd, UK. The dynamics of gelation was determined upon time and temperature (70, 75, 80 and 85ºC) by a Phaar Physica MCR 300 rheometer, with controlled stress as well as frequency sweeps. Surface hydrophobicity (S0) of protein dispersions was determined according to the method of Kato & Nakai (1980) [1]. The concentration of sulfhydryl (SH) groups according to Ellman’s procedure (1959) with the modifications of Shimada & Cheftel (1988) [2], [3]. The gelation temperature of EW did not vary substantially by HIUS treatment as well as the gelation properties studied here. The formation of aggregates from protein solutions was accelerated by HIUS and their sizes sizes were bigger. This fact could be attributed to the increase in the hydrophobicity of the protein. Thus HIUS could allow improving functional properties of EW.