In this study, pulsed electric field (PEF) treatment of beer, effectiveness of PEF treatment on microbial inactivation, effects of PEF treatment on sensory properties, and detection of electrode material migration were explored. Beer samples were treated by PEF for the inactivation of natural flora and inoculated cultures of Saccaromyces uvarum, Rhodotorula rubra, Lactobacillus plantarum, Pediococcus damnosus, and Bacillus subtilis. Inactivation induced by the PEF treatment was 0.5, 4.1, 4.3, 4.7, 5.8, and 4.8 log 10 colonyforming units/mL in the above microorganisms, respectively (P < 0.05). There was a significant increase in the amount of Cr, Zn, Fe, and Mn ions in the beer samples after PEF treatment (P < 0.05) leading to a statistically significant degradation in flavor and mouth feel. Further studies are needed to optimize electrode materials and PEF treatment to minimize or eliminate this degradation.

A group of selected enzymes were subjected to continuous pulsed electric field (PEF) treatments to evaluate the inactivation effect of PEF. For a treatment time of 126 s, 51.7% and 83.8% of pepsin was inactivated at 37.0 kV/cm and 41.8 kV/cm, respectively. Enzyme activity of polyphenol oxidase decreased 38.2% when treated at 33.6 kV/cm for 126 s. Enzyme activity decreased 18.1% and 4.0% for peroxidase treated at 34.9 kV/cm and chymotrypsin treated at 34.2 kV/cm, respectively. No significant change in lysozyme activity was observed after PEF from 0 to 38 kV/cm for 126 s. Both PEF and the induced heat contributed to the observed inactivation effect, depending on the properties of enzymes and test conditions.