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J. RASO-PUEYO, Food Technology, University of Zaragoza, C/ Miguel Servet , 177, Zaragoza, 50013, Spain

Nonthermal methods for food preservation are under intense research to evaluate their potential as an alternative or complementary process to traditional methods. During nonthermal processing the temperature of the food is held below the temperature normally used in thermal processing, therefore the decline in food quality is minimal. Besides preserving food quality, new nonthermal technologies have to achieve an equivalent or preferably enhanced safety level as compared with the procedures that they replace. Overall, most nonthermal preservation techniques are highly effective in inactivating vegetative forms of bacteria, yeast, and molds. However, bacterial spores and most enzymes remain difficult to inactivate by these procedures, so their use for food preservation is still limited. To extend the use of nonthermal food processes, combinations of these technologies with traditional or other emerging technologies are being studied. This approach, known as "hurdle technology," has already been successfully applied using traditional techniques of food preservation. This overview will deal with the most promising combinations that include nonthermal methods, such as high hydrostatic pressure, ultrasound, and pulsed electric fields.