Pulsed electric field treatment applied to microbreweries for processing craft beer

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Heat treatment methods such as thermal pasteurization are predominantly utilized as a means to inactivatespoilage microbes. However, heat treatment methods are energy intensive and adversely affect nutritional andorganoleptic quality of the preserved food. In the recent years non-thermal processes like pulsed electric field(PEF) technology has been investigated for commercial applications. PEF devices consist of a pair ofelectrically conductive metal electrodes, separated by a known gap distance. High voltage pulses are applied toone of the electrodes while keeping the other electrode at ground potential. The resulting electric field causesirreversible breakdown of cell membrane; hence microbial inactivation.Brewery regulations in Canada do not necessitate pasteurization of craft beer; hence, PEF processing finds apotential application in the brewing industry. PEF treatment being a non-thermal, the fresh like taste and thenutritional value are better retained than with conventional thermal pasteurization. However, due to the flow ofcurrent during the PEF processing, metal ions are released from the electrodes. The amount of metal releaseddepends on the type of product, the specific composition of electrodes and the type of pulses used. Thisproposed research investigates the applicability of the PEF processing to craft beer, through a pressurizedprocessing chamber that has been designed to eliminate release of most metal ions.With a strong cooperation between the University of Waterloo and Innocente Brewing Company, we areconfident in demonstrating the effectiveness of the PEF pasteurization for craft beer, using the modified UW'sPEF facility. Systematic tests with precise control of the applied pulse, treatment time, and other parameters,like medium temperature and energy are being considered to evaluate metal ions released during the PEFprocessing and their consequent effect, if any, on the taste and the shelf life. The knowledge and technologythat are expected as outcome of this research are of direct benefit for microbreweries in promoting their newpremium products.