Liquid Whole Egg Ultrapasteurization by Combination of PEF, Heat, and Additives

This paper evaluates the possibilities of combined processes based on the successive application of pulsed electric fields (PEF) and heat, in the presence of additives (EDTA and triethyl citrate (TC)), as an alternative to liquid whole egg (LWE) industrial ultrapasteurization. Firstly, the lethality of the combined processes on two heat-resistant microorganisms (Salmonella Senftenberg 775W and Listeria monocytogenes) was evaluated. Secondly, the impact of these processes on LWE physicochemical and functional properties was determined. In the best-case scenario, the application of PEF (25 kV/cm; 200 kJ/kg) followed by heat (60 °C/3.5 min) to LWE added with 10 mM EDTA or 1 % TC inactivated around 5-Log10 cycles of Salmonella Senftenberg 775W and L. monocytogenes, while industrial ultrapasteurization (70–71 °C/1.5 min) provided 3.5–5.0-Log10 reductions of both microorganisms. LWE treated by the combined processes was less viscous, showed better foaming and emulsifying properties, and formed more mouthfeel gels than the ultrapasteurized product. On the other hand, LWE treated by the combined process in the presence of TC increased by 90 % the foaming stability, and the treated in the presence of EDTA improved by 10 % the emulsifying capacity of non-treated LWE, whereas thermal ultrapasteurization dramatically reduced both properties. Therefore, the application of PEF (25 kV/cm; 200 kJ/kg) followed by heat (60 °C/3.5 min) in the presence of 1 % TC or 10 mM EDTA could be promising alternatives to the industrial ultrapasteurization since similar or even higher safety level with a lower impact on LWE quality was obtained.