European R&D Efforts Yield Food Industry Innovation

Eureka is the name of a European initiative that promotes co-operative hi-tech research into cutting edge, non-military processes and services. Launched in 1985, the organization helps find partners in industry and research to supply funding, technical expertise, manufacturing or marketing facilities. The following are current Eureka R&D projects of interest to the food industry:

Innovative Extruder
Project 1274: The company Valeurex has developed a food extruder that uses counter-rotating twin screws to press material through a die. The design provides higher throughput than existing single or twin screw feeders and should reduce the cost per kilogram of extruded foods and provide a viable solution to the extruding of high and low viscosity foods.

The design also enables extrusion of foodstuffs with a relatively low water content, which would cut drying costs. The faster throughput means foodstuffs stay in the compressing barrel for less time before passing through the die. This will reduce the loss of nutritional value through denaturing by heat because material is heated in the barrel to ease flow through the die. Some heat is generated by the compressing action of the screw on the material but additional heat is also often applied to the barrel.

Lead partner in the project, Lalesse Machinebouw based in Arnhem, manufactures complete snack food processing lines including a range of extruders. It is supplying the main engineering effort in conjunction with Swiss-based Benzler AB, which is contributing the drive design. Other partners in the project are the Agricultural University of Lublin, which has contributed research data on the extruding of vegetable foods; the Institute of Food Processing Machinery in Warsaw, which designed the barrel section; and Landbouw University Food Science Department in Wageningen, which is performing tests on materials under compression.

Powder Granulation
Project 1788: The company Granule is developing a new powder granulation technology. This will produce full spherical, regular shaped granules with a narrow size distribution. Granules are usually made by atomizing and drying an aqueous suspension using spray nozzle or spinning disc techniques. Other traditional granulation methods include fluidized bed or extrusion through a grid. Current methods lead to a wide range of particle sizes with some hollow or irregular shaped samples.

During processing this can cause wastage and problems such as demixing and size segregation. It also causes mechanical problems such as flaws in pellets and other compressed products while the relatively wide size distribution of the granules makes sieving essential. The taste of powdered foods can be affected by granule size while processing, transporting and pelleting of granules is helped if grain size is even.

The new process will produce full spherical granules from an aqueous suspension. It takes place in a drying tower with a new design of rotating disc that eliminates the creation of dust. It has already produced good results with cocoa powder. Aqueous solution is introduced into the top of a vertical, spinning dispenser and discharged through holes in the sides of the dispenser by centrifugal force. It then flows regularly over the surface of the discs, breaking up into droplets at the rim.

Key to the narrow size distribution and sphericity is the thickness of the liquid layer on the disc surface. Granule will study the behavior of aqueous suspensions and make it possible to use a high solid to liquid ratio in the new system. This will reduce drying time and ensure the production of dense granules. Besides improving quality of powders, the development will also save waste, time and energy in separating unsuitably sized granules.

A control system will also have to be developed for the drying tower. A pilot plant comprising drying tower and classifier with a capacity of 10-20kg/h will be constructed to refine the design by practical application.

The project is being led by Professor Heinrich Hofmann, director of the department of materials and laboratory of powder technology at the Federal Polytechnic of Lausanne, EPFL. The department will be responsible for designing the drying system, researching suspensions and analyzing the spray-dried droplets. EPFL has more than 10 years' experience in the field of spray drying at laboratory, pilot and production level.

Other partners concerned with the food aspects of this project are Prodima, which is constructing the pilot plant; Hochschule Waedenswil (HSW), which will adapt the new technology specifically for food and pharmaceutical applications; and Global Powder, which owns the patent for the atomization process. HSW offers experience in mixing, granulation and drying of foodstuffs with special knowledge of equipment and process design.

Smoking And Roasting
Project 1843: The company Combi-Roast is developing an innovative and environmentally friendly automatic method for the combined smoking and roasting of special, high quality foodstuffs using horizontal air circulation. Currently, say the partners, there is no combined system on the world market for smoking and roasting and the project should open up new opportunities for food producers. The problem is to combine the relatively low temperature over a long time smoking cycle with the greater heat and shorter time scale for roasting.

The partners see the solution in computerized control. Advanced programming can control airflow, temperature and humidity in two separate cycles to suit the two cooking methods. The two cycles are interleaved to minimize drying and weight loss of the food. Airflow will be horizontal across the cabinet so flow and direction can be controlled. Odor removal and filtering will have to be developed to eliminate pollution of the atmosphere. The project will also develop an odorless, environmentally friendly browning agent.

Lead partner is Bayha and Strackbein (BASTRA) based in Germany. Its UK agent is Redmond's, based in Northampton.

For more information about the specific projects, visit Eureka's website at: http://eureka.belspo.be/criteria.html.