Processing of carbonated beer by pulsed electric fields

The microbial shelf-life of carbonated beer can be extended after processing by pulsed electric fields (PEFs). Being a non-thermal preservation method, the fresh-like taste and original nutritional values are better retained than with the conventional thermal pasteurization. However, due to the flow of current, metal ions will be released from the electrodes during the processing. The presence of these ions in the PEF-processed beer accelerates its aging and may affect the organoleptic stability. Hence, this study evaluates the metal ions released during PEF processing under different test conditions. It has been found that the amounts of iron ions released under the conditions tested are well below the iron concentration found in many consumable products in the market. The effect of processing zone temperature in the range 1-30^oC on the concentration of metal ions is not significant; thus exploring the synergistic effect of both PEF and temperature on microbial killing is possible.