Oregano enriches the flavor of tomato sauce, juniper is a welcome addition to marinated meat, and sauerkraut tastes best with cumin. No dish is complete without herbs and spices. But seasonings need to be healthy in addition to having the right flavor, aroma and color. All your favorite spices have to be purified before you buy them.

Researchers from the Institute of Agricultural and Food Biotechnology (IBPRS) in Poznań, western Poland, have found a way to continuously decontaminate herbs and spices, killing microorganisms to levels that comply with the most stringent standards.

"Household and industrial use of seasoning has increased significantly over the past few years," says Associate Prof. Marian Remiszewski, Ph.D. (Eng.), who manages the research team at the Institute's Department of Food Concentrates. This has resulted in more companies producing, importing or packaging herbs and spices and preparing seasoning mixtures. "Many methods to reduce the content of microorganisms in herbs and spices have been devised around the world and their effectiveness varies considerably," says Remiszewski. "Chemical, thermal and other methods are used as is irradiation. Consumers are particularly anxious about irradiation, which is why there has been increasing interest in using steam sterilization. Most countries are familiar with the technology, but the equipment is very pricey and certainly beyond the reach of the average Polish producer."

The process devised by the Poznań team utilizes steam to sterilize all types and sizes of seasoning from roots and fruits to seeds and powdered herbs and spices. The process takes place inside a continuously running reactor. "The raw product is exposed to injected saturated and superheated steam as it passes through the reactor," says Remiszewski. One cycle is usually enough to reduce the amount of microorganisms to acceptable levels. If not, the process is simply repeated.

The process can handle between 50 to 500 kilograms per hour, depending on the type of seasoning and the degree of contamination. The sterilized product is then dried to the required humidity. Too much moisture can lead to reinfection. The product is finally cooled to 70 degrees Celsius for maximum effectiveness.

The technology was developed by Eugeniusz Korbas, Franciszek Kwiatkowski, Marian Remiszewski, Zbigniew Liszkowski, Ryszard Przygodzki and Ireneusz Płowens, all of whom work in research at the Department of Food Concentrates at the IBPRS in Poznań. The technology has been patented in Poland and is being used in the Experimental Section of the Department, which decontaminates seasoning for companies.

The technology has been recognized with a number of awards and prizes, including the Minister of Agriculture and Rural Development Award for achievements in agriculture, rural development and rural markets; a silver medal at the 56th World Innovation Contest Brussels-Eureka in Brussels; a silver medal at the ARCA International Exhibition of Inventions in Zagreb; a silver medal at the Inventika 2007 International Exhibition of Inventions, Scientific Research and New Technologies in Bucharest; and a bronze medal at the 36th International Exhibition of Inventions, New Techniques and Products of Geneva. The technology has also won a competition called "Research and Development Centers for the Economy and Society."

Bogusława Szumiec