A clear trend toward more natural food preferences along with increasing safety regulations has increased interest in high pressure treatment of packaged foods, according to the company. HPP-treated, packaged food passes through a pressurized vessel, which denatures pathogens by delivering 87,000 psi of water pressure for a specified dwell time. HPP is used by processors as a food-safety intervention to control pathogens including Listeria and Salmonella while increasing shelf-life by as much as four times of non-treated products. Because the process is conducted under ambient temperature, even heat-sensitive food products can be treated with this method.
Before Multivac’s newest innovation, HPP was typically conducted in a separate manufacturing stage, which some processors consider to be disruptive to throughput. Using patent-pending technology Multivac has developed a solution to integrate high pressure equipment into packaged food lines, according to Tobias Richter, product manager in the Systems Business Group for MULTIVAC Sepp Haggenmüller GmbH. The solution includes the high pressure unit (one or HPP vessels), which has been developed by the ThyssenKrupp daughter company, Uhde High Pressure Technologies, as well as an automation concept to integrate the process into packaging lines designed to meet the demands of the food industry. Multivac also offers a high pressure compatible packaging concept for modified-atmosphere packaging applications.
With the integration solution developed by Multivac, the finished food packages are automatically loaded into transport containers, HPP-treated, and then automatically unloaded before being dried and undergoing necessary labeling and packed into cartons. "In this way, it is for the first time that we can process large, industrial scale production quantities fully automatically in a quasi- continuous operation," Richter says.
Efficient use of the space inside the HPP vessel is crucial to achieving maximum productivity, Richter says. “Since the high pressure equipment is round for reasons of optimizing the distribution of pressure forces, the loading pattern also has to be designed accordingly.” With a favorable pack shape it is possible to treat up to four tons of packaged food per hour in the high-pressure equipment. Multivac engineers work with customers to develop the optimum package shape and a customer testing facility is available at its Uhde High Pressure Technologies office in Hagen, Germany.