ABSTRACT

The microbial stability and safety of most traditional and novel foods depend on a combination of several preservative factors (called hurdles), which the microorganisms present in the food are unable to overcome. This is the so-called hurdle effect, first introduced by Leistner [1]. Figures 15.1 and 15.2 show the visualized concept of hurdle technology, and these indicate when the microbe passed over the hurdles or stairs, and when it was exhausted and unable to perform its physiological process or died. The hurdle effect is of fundamental importance for the preservation of foods, since the hurdles in a stable product control microbial spoilage and food poisoning as well as desired fermentation processes [1,2]. Leistner and co-workers acknowledged that the hurdle concept illustrates only the well-known fact that complex interactions of temperature, water activity, pH, redox potential, etc., are significant for the microbial stability of foods. From an understanding of the hurdle effect, the hurdle technology [3] is derived, and it allows improvements in the safety and quality of foods, by deliberate and intelligent combinations of hurdles. Over the years, the insight into the hurdle effect has been broadened and the application of hurdle technology extended. In industrialized countries, hurdle technology is currently of particular interest for minimally processed foods, whereas in developing countries it is of interest for foods storable without refrigeration, due to stabilization by hurdle technology; thus at present hurdle technology has paramount importance. The application of deliberate and intelligent hurdle technology is now advancing rapidly worldwide. This concept is synonymously called food preservation by combined methods, combined processes, combination preservation, or combination techniques. Special expressions for this concept have been coined in different languages, for example Hürden-Technologie in German, hurdle technology in English, technology des barrières in French, tecnologia degli ostacoli in Italian, tecnologia de obstaculos in Spanish, zanglangishu in Chinese. Recently, the term hurdle technology has been most often used. Visualization of hurdles on microorganism considering each preservation effect is a hurdle. https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429091483/664b9b5a-638a-4ec7-b69b-5d34889988bd/content/fig15_1_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> Visualization of hurdles on microorganism considering each preservation effect is a stair. https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429091483/664b9b5a-638a-4ec7-b69b-5d34889988bd/content/fig15_2_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>