XVII. European Symposium on the Quality of Eggs and Egg Products, Edinburgh, İskoçya, 3 - 05 Eylül 2017, ss.5
The physicochemical, functional properties and rheological behaviours of ultrasound (US) treated liquid whole eggs (LWE) were investigated. LWE were treated with ultrasound for 3 or 6 min of exposure time and 150 W or 375 W using a Hielscher Ultrasonic Processor. The pH, dry matter, water activity (aw), colour analysis (L*, a*, b*), relative foaming capacity (RWC), foam stabilityand rheological behaviors of the US treated and untreated LWE were compared. The flow ramp, oscillation amplitude, oscillation frequency and temperature ramp (40 and 80 °C) were measured using an oscillatory rheometer. Shear rate ranged from 0.01 to 100s-1at 150 W. US treated and non-treated LWE samples behaved as non-Newtonian fluids displaying shear thinning which were best fitted to a Herschel-Bulkley flow model. Significant differences (P<0.05) in physicochemical and functional properties of LWE were recorded. US treated LWE had a significant reduction in viscosity from 250 to 120 mPa.s, except when treated at 150W for 3 min, while better foaming properties (control groups 470±17.32; 150 W – 3 min US493±11.54; 150 W – 6 min US 508.33±12.58; 375 W – 3 min US 480±14.14 and 375 W – 6 min US 486±15.27) were obtained for all US treatments without any significant negative effect on physicochemical composition. The higher US treatment of LWE caused significant reduction in a*value, control 4.11±0.02; 150 W – 3 min US4.07±0.01; 150 W – 6 min US 3.93±0.03; 375 W – 3 min 3.91±0.03 and 375 W – 6 min US 3.89±0.03. The pH, dry matter, aw, and RWC of treated LWE ranged from 7.17±0.05–7.22±0.08; 24.91±0.29–25.01±0.57; 0.95±0.009–0.96±0.008,and 470±17.32–508.33±12.58, while untreated LWE measurements was 7.22±0.08; 25.01±0.57; 0.956±0.001 and 470±17.32respectively. The results suggest that treatment of LWE with ultrasound significantly improves some of the functional properties.