Hurdle technology

Leistner, L. (2000) Basic aspects of food preservation by hurdle technology . International Journal of Food Microbiology, 55, 181-186. 

Hurdle technology Involves manipulating various growth-controlling parameters in a manner such that growth of microorganisms will not occur each parameter serves as a hurdle to microbial growth (based on Fennema, 1996). 

Leistner, L. 1995. Use of hurdle technology in food processing Recent advances. In Food Preservation by Moisture Control Fundamentals and Applications (G.V. Barbosa-Canovas and J. Welti-Chanes, eds), pp. 377-396. Technomic Publisher, Lancaster, PA. 

Leistner, L. 2002. Update on hurdle technology. In Engineering and Food for the 21st Century (J. Welti-Chanes, G.V. Barbosa-Canovas, and J.M. Aguilera, eds), pp. 615-629. CRC Press, Boca Raton, FL. 

Lothar Leistner and Grahame Gould, Hurdle Technologies Combination Treatments for Food Stability, Safety, and Quality (2002)... 

The storage life of foods is influenced significantly by the water activity in the product. Intermediate-moisture foods, which have values between 0.6 and 0.9, have drawn considerable attention [31]. Many of the intermediate-moisture foods have reduced moisture contents and are palatable without the need to rehydrate them [32], Microbial proliferation is terminated at values below 0.6. Even at higher moisture levels, the effect of lowered a has a synergistic effect in prolonging shelf life when combined with other methods of preservation. This technique of combining multiple preservation techniques to extend the shelf life stability of foods is known as the hurdle technology. 

Leistner, L., Hurdle technology applied to meat products of the shelf stable product and intermediate moisture food types. In Properties of Water in Foods, Sinators D. and Multon J.C., Eds. Martinus Nijhoff Publishers, Dordrecht, the Netherlands, pp. 309-329, 1985. 

The D value is the time required at a set temperature for a decimal reduction (i.e. one log or 90%) in the population numbers of a known organism. The size of the D value depends on the temperature, the microorganism and the other parameters in the beer that affect microbial grown (see Section 12.5.1 on hurdle technology). A higher temperature or lower pH will lead to a lower D value. A D value can be expressed in minutes or seconds. 

Some examples of different CQPs and their specific microbiological problems along with possible corrective measures are found in Table 10.1. As an example, detection of one cell of Saccharomyces in a bottle of sweet, unfortified wine may be enough to cause refermentation in the bottle. In this case, a preventative measure that could be taken would be assurance that the bottling line was correctly sterilized and that sterile filtration equipment functioned properly. Additional measures would be inclusion of sorbates to limit potential yeast growth. Known as hurdle technology, this concept relies on implementation of several preventative measures as... 

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