A CSIR-led R&D consortium has successfully developed a pasteurisation system that greatly reduces the risk of Salmonella enteritidis infections from eggs and may also be effective against the virus that causes Avian influenza, according to preliminary laboratory data. This has led to the first sales of pasteurised, whole shell eggs in South Africa.

Backed by the Innovation Fund, the consortium pooled the skills of food scientists and microbiologists at the CSIR and sensory evaluation experts at the University of Pretoria. The research team included members of the SERA Food Science and Technology Task Team, as well as design engineers from Delphius Technologies, specialists in developing industrial microwave ovens and commercial experts from Eggbert Eggs, the country's second largest egg producer.

Increased restrictions in administering chronic feed antibiotics to chickens have been commensurate with a rise in the incidence of salmonella and other pathogens. According to the World Health Organisation (WHO) infected eggs contribute up to 40% of reported food poisoning cases in Europe, and many countries have had to take measures in the recent past to contain salmonella outbreaks.

CSIR Executive Director for Biosciences, Dr Gatsha Mazithulela, says an increasing number of food safety problems and rising consumer concerns have led to an intensified research focus on food safety issues. While healthy individuals will recover from salmonella poisoning, although they may become extremely ill, the consequences of infection could be more serious in immune-compromised individuals. The high levels of HIV infection in South Africa places it at risk of increased salmonella-related mortalities.

The new pasteurisation process ensures that the eggs are kept at exactly the right temperature to destroy the micro-organism, without causing significant changes in the composition, taste or functionality of the eggs.

The heat in the system is generated by microwave and hot-air technology, using a custom-designed oven cavity and phased process developed by Delphius Technologies. As micro-organisms are sensitive to variables such as shape, mass, yolk positioning and heating profile, the most challenging part of the project was optimising the heating curve and hot spot identification.

The consortium expanded its initial research objectives to include testing on a low virulence strain of the Avian influenza virus as a result of Avian flu warnings by the WHO. "Preliminary results from these trials indicate that the new pasteurisation technology also destroys the Avian influenza pathogen. While all indications are that South Africa currently remains free of Avian flu, we are encouraged by these results and by the future potential of this technology as one possible preventative measure," says Mazithulela.

The consortium has agreed on a commercialisation strategy that includes equity partnerships addressing black economic empowerment.

While consumers will soon be able to buy pasteurised eggs from selected retailers as a result of this new technology, the consortium is in discussion with local retailers, caterers and restaurants to consider using and selling pasteurised eggs. For more information contact Tlhogi Mokhema on +27 12 841 3716.