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Microbiological efficacy in liquid egg products of a UV-C treatment in a coiled reactor

de Souza, Poliana Mendes, Müller, Alexandra, Fernández, Avelina, Stahl, Mario
Innovative food science & emerging technologies 2014 v.21 pp. 90-98
Escherichia coli, Listeria innocua, Salmonella Enteritidis, bacteria, egg products, egg yolk, eggs, food industry, foods, molds (fungi), nonthermal processing, pasteurization, shelf life, spoilage, storage time, ultraviolet radiation, yeasts
The feasibility of ultraviolet processing as a non-thermal pasteurization technique for liquid egg products was investigated. Inactivation of Salmonella subterranea DSM 16208 followed comparable kinetics than Salmonella enteritidis, therefore it was used as a non-pathogenic surrogate. The influence of the dose on the inactivation of S. subterranea DSM 16208, Escherichia coli DH5α and Listeria innocua WS 2258 in liquid egg fractions was evaluated on a laboratory scale recirculating UV-C treatment coiled reactor UVivatec® Lab (Bayer Technology Services GmbH, Leverkusen, Germany) and a higher scale laboratory device (coiled tube reactor MRI2010, designed and assembled at the Max Rubner-Institut, Karlsruhe, Germany). Analogous inactivation kinetics were observed for all microorganisms, in which inactivation curves followed a logarithmic decay and changed over to a tailing phenomenon after some time of UV-C exposure. Comparable inactivation behavior and doses to inactivate the selected microorganisms were detected for whole egg, flowing from 9.5 to 20Lh−1. Highest doses were necessary to attain a 5 Log reduction on egg yolk. UV-C processing resulted in a shelf life extension of liquid egg up to 8weeks at 4°C, which corresponds to a storage period 4 times higher than the recommended for pasteurized LWE.This novel UV-C system can be applied successfully to the Food Industry. UV-C can be effectively used to reduce the number of spoilage and pathogenic bacteria, as well as yeasts and molds in different kinds of food products.