Proceedings Volume 2010 (format .pdf) - SimpBTH

COMBINED SYSTEM, PEF AND UV, FOR THE INACTIVATIONOF PATHOGENIC MICROORGANISMS IN LIQUID FOODPOPA M., TUDORACHE A., BRINDUSE E., CRAMARIUC R., KONTEK A.,MITELUT A., FOTESCU L., CRAMARIUC B., GEICU M., NISIPARU L.ABSTRACTThe PEF treatment is a non thermal food preservation technology, based on the use ofpulsed electric fields, to inactivate pathogens in food and to control the pathogen content of thetreated products. This technology is highly valued for its ability to prolong the shelf life of the producttreated without use of heat and also to keep the value of sensory and nutritional qualities of theproduct and the microbiological control of food. PEF technology has no limitations related to thespread of lethal microorganisms in the treated product, for example, in heat treatment where thisphenomenon can take place by conduction or convection. The electric field has a density, whichenables a rapid and uniform inactivation of lethal microorganisms throughout the product volume.UV irradiation has been used for decades to disinfect water and is an effective method formicrobial decontamination of surfaces and food packaging.The Food and Drug Administration (2000) approved the UV irradiation as an independentmethod for preserving fruit juices, unless turbulences occur in the process. This condition is notrequired if the UV exposure is not the only decontamination factor.This paper gives the PEF and UV treatment, or a combination of PEF and UV inactivationof microbial liquid food.Experiments were performed using the micro-organisms: yeast, lactic acid bacteria andacetic bacteria in the systems: PEF alone, UV alone, UV + PEF and PEF + UV combined.The result of these experiments was that it can get a total inactivation of microorganisms inthe combined UV + PEF, leading to the possibility of increasing the quality of liquid foods in relationto thermal pasteurization.Key words: Pulsed Electric Field (PEF); UV radiation; microbial inactivation; liquid food.1. IntroductionRecently the market demand of fresh or minimum processed products hasrapidly increased. Currently, heat processing is the most used method forinactivating microorganisms that allows increased product life on the shelf.However, this process can adversely affect the nutritional and sensory qualities offood [5]. In this context, recent years have been paid attention to non-thermaltechnologies (ie PEF, UV), For the preservation of beverages, thanks to theirpotential on inactivation of pathogenic microorganisms. In addition, they can helpminimize the loss of quality in terms of taste, color and nutritional value [2].The PEF treatment is a non thermal food preservation technology, based onthe use of pulsed electric fields, to inactivate pathogens in food and to control thepathogen content of the treated products. This technology is highly valued for itsability to prolong the shelf life of the product treated without use of heat and also to306