Stabilization of foodstuffs and plant-based extracts

Fraunhofer IGB develops new product-friendly processes for sterilization and hygienization based on physical principles. In the “Aseptic Technologies” working group, food technologists and process engineers, and also other specialists, bring together their expertise to complement their research strengths. This interdisciplinary approach results in the development of new technological solutions for the product-friendly inactivation of contaminating microorganisms. Preservatives are not required for this, so foodstuffs retain their vitamins and there are no adverse effects on basic cosmetic or pharmaceutical substances.


From inactivation mechanisms to industrial implementation

The emphasis of our work here is, in the first place, to understand and describe the mechanisms by which contaminating microorganisms are inactivated during the course of the process; and secondly the interactions of the various parameters in the system (e.g. temperature, pressure, viscosity, pH value etc.). In this way the methods can be technologically optimized and implemented in a production process.

Two technological approaches are currently the main focus of our developments: microwave and pressure change technology, PCT for short. The conception, development and testing of these processes from laboratory scale to piloting on an industrial scale always takes place in close cooperation with partners from industry. In this way our scientists can respond directly to the precise requirements of the end-users of the applications.

Pressure change technology

The pressure change technology (PCT) for the preservation of liquid foodstuffs such as fruit juices or wine is being further developed at the Fraunhofer IGB. In this process, the product is mixed with an inert gas such as nitrogen or argon under pressure followed by an abrupt pressure release. The reduction of microorganisms in fruit juices and other model liquids was successfully demonstrated by cooperation partners using batch and semi-continuously operating process units.

A new facility for application studies on beverages, fruit plant extracts and suspensions containing active substances (such as cosmetic and pharmaceutical preparations) has been recently commissioned.


Microwave pasteurization.
The test facility, integrated into an existing pasteurization system at the University of Hohenheim.

Microwave heating is a common method for preparing food both in households and industrial production processes. However, most industrial processes are designed for batch operating units. Our team at Fraunhofer IGB has developed this technology further leading up to a continuously operating system for the preservation of liquid products. Because new applications for microwave technology depend very much on the material to be processed, our group has developed models for various applications of microwaves in the foodstuff industry and has examined these by conducting scientific studies.