Pasteurized under vacuum

The newest development from Bühler Barth AG is its CCP nut and almond sterilization system.

At the Interpack 2008, the youngest Buhler affiliate Bühler Barth AG will present the new CCP nut and almond sterilization system at the booth of the Chocolate & Cocoa business unit. This latest innovation was developed especially with the continuing salmonella problem in mind, which has particularly hit the almond industry in the U.S.

Gentle process sought

True - several almond pasteurizing processes have already been approved by the Almond Board of California (ABC). But they all have the drawback that the natural appearance of the almonds is degraded or even destroyed by pasteurization. The goal for the developers at Buhler Barth was therefore to find a gentle process which would allow the salmonella count to be slashed by a value "better than logarithm 4" without affecting the natural appearance of the almonds. In developing the new process and the required machine, Bühler Barth AG was supported by Dr. Rainer Perren from the company RPN Foodtechnology AG in Grosswangen, Switzerland. In addition, scientists from the Faculty of Microbiology of the Swiss Federal Institute of Technology Zurich were involved in the inoculation of the test specimens and their microbiological analysis.

Straightforward process

The result of this development effort is the new CCP nut and almond sterilization system. A batch of almonds or nuts is exposed in the product chamber of the new machine to a certain vacuum. Then saturated steam is injected. The negative pressure and the saturated steam atmosphere are maintained for a certain retention time. Once the steam treatment has been completed, the vacuum is maintained in order to reduce the moisture content of the product. Then, the product chamber is vented and the batch is discharged from the machine.

Moisture content determines appearance

The special innovation of the new process resides in the fact that pasteurization takes place in a vacuum. As a result, the product absorbs extremely little moisture during pasteurization. In conventional processes, up to 10 percent moisture are added to the product. In the CCP process, this value is less than one percent.

The low moisture addition rate ensures that the natural appearance of the almonds and nuts is retained. If almonds absorb too much moisture, this may in the worst case even cause the shells to be detached. In the CCP process, all the shells retain their natural color. This effect also applies to all other nuts or oil¬containing seeds such as sunflower seeds, melon seeds, or similar produce.

Laboratory version at the Interpack

The special value of this innovation for customers lies in the reliable pasteurization of the raw products. The CCP process subjects the raw product to a much more intensive pasteurizing action than is even demanded by strict U.S. legislation. Since similar salmonella accidents have happened also in other areas such as the peanut industry, similar legislation must be expected also there. At the Interpack 2008 in Düsseldorf, Buhler Barth will display a laboratory version of the new CCP nut and almond sterilization system. Buhler Barth will later on make this system available to customers in its pilot plant for conducting tests. The test results can then be upscaled directly to any commercial production system.

Buhler is a global leader in the field of process engineering, especially technologies for producing foods and engineering materials. Buhler sells into over 140 countries and has some 6900 employees worldwide. In fiscal 2007, the Group generated sales of CHF 1770 million.


For more information on the new system, please contact:
Jürgen Fischer, Member of the Executive Board of Bühler Barth AG in Freiberg
T +49 7141 705 201, F +49 7141 705 100,

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