Control of Salmonella on almonds and pistachios

After salmonella outbreaks in the U.S.A. linked to almonds, pistachios and peanuts, the FDA wants a guaranteed “kill step” for these products, and more important, expects producers to validate all such processes, proving that the kill step works. A new thermal process for nuts has been developed by Bühler Barth AG in cooperation with RPN Foodtechnology AG. The Control Condensation Process (CCP) is undertaken in a steam atmosphere and aims the reduction of Salmonella on pistachios of at least 5 log. The objective of our experiments was to buildup small equipment enabling us to reproduce the CCP process in the laboratory with exactly the same characteristics concerning time, temperature and pressure of the heat treatment. Using this set-up, the killing effect of the process on two Salmonella strains (S. montevideo, S. enteritidis) and a non-pathogenic surrogate (Enterococcus faecium) can be measured. The trials are carried out on pistachios with and without shell and enabled the authorization of the full-scale process by the Californian Authority.