In our experiment whole egg powder samples (infected with Salmonella Enteritidis for microbiological tests) were treated at 50.38–54.62°C for 6.41–24.09 h and tested for decrease in Salmonella count or changes in their solubility and colour. Central Composite Rotational Design (CCRD) was used in our tests. In all tests performed within the testing range we achieved a decrease in Salmonella count of at least 5 magnitudes and in cases when the samples were treated at min. 52.5°C for at least 9 h no viable Salmonella could be detected in the whole egg samples at the end of treatments. Our measurements have shown that deterioration of solubility and discolouration was signifi cantly affected only by the temperature change (p<0.05).
Department of Refrigeration and Livestock Products Technology, Faculty of Food Science, Corvinus University of Budapest, Menesi ut 43-45, 1118 Budapest, Hungary
1. Baron F., Gautier, M., Brulé, G., Rapid growth of Salmonella Enteritidis in egg white reconstituted from industrial egg white powder. J. Food Protect., 1999, 62, 585–591.
2. Box, G.E.P., Draper, N.R., Empirical Model-Building and Response Surfaces. 1987, John Wiley and Sons Inc. NY.
3. Brackett R.E., Beuchat L.R., Survival of Listeria monocytogenes in whole egg and egg yolk powders and in liquid whole eggs. Food Microbiol., 1991, 8, 331–337.
4. Granato D., De Castro I.A., Ellendersen L.S.N, Masson M.L., Physical stability assessment and sensory optimization of a dairy- -free emulsion using response surface methodology. J. Food Sci., 2010, 75, 149–155.
5. Jung Y.S., Beuchat L.R., Survival of multidrug-resistant Salmonella typhimurium DT104 in egg powders as affect ed by water activity and temperature. I nt. J. Food Microbiol., 1999, 49, 1–8.
6. Laroche C., Fine F., Gervais P., Water activity affects heat resistance of microorganisms in food powders. Int. J. Food Microbiol., 2005, 97, 307–315.
7. Lechevalier V., Jeantet R., Arhaliass A., Legrand J., Nau F., Egg white drying: Infl uence of industrial processing steps on protein structure and functionalities. J. Food Eng., 2007, 83, 404–413.
8. LiCari J.J., Potter N.N., Salmonella survival during spray drying and subsequent handling of skimmilk powder. III. Effects of storage temperature on salmonella and dried milk properties. J. Dairy Sci., 1970, 53, 877–882.
9. Magdelaine P., Braine A., International and European overview of egg production and consumption., Productions Animales, 2010, 23, 111–121.
10. Németh Cs., Horváth K., Drobecz Á., Friedrich L., Pásztor-Huszár K., Balla Cs., Calorimetric study of changes induced by preservatives in liquid egg products. Pol. J. Food Nutr. Sci., 2010, 60, 347–352.
11. Németh Cs., Mráz B., Friedrich L., Suhajda Á., Janzsó B., Balla Cs., Microbiological measurements for development of a new preservation procedure for liquid egg., Czech J. Food Sci. (in press).
12. Nwabueze T.U., Review article: Basic steps in adapting response surface methodology as mathematical modelling for bioprocess optimisation in the food systems. Int. J. Food Sci. Technol., 2010, 45, 1768–1776.
13. Petrak T., Medic H, Novakovic P., Botka-Petrak K., Bacteriological contamination of egg products after thermal preservation processes. Acta Aliment., 2000, 29, 315–322.
14. Talansier E., Loisel C., Dellavalle D., Desrumaux A., Lechevalier V., Legrand J., Optimization of dry heat treatment of egg white in relation to foam and interfacial properties. Food Sci. Technol.-Lebensm. Wiss., 2009, 42, 496–503.