The Federal Court of Canada has ruled that Simplot’s use of pulsed electric field (PEF) technology in French fry processing does not infringe Canadian Patent No. 2,412,841 held by McCain Foods.

The case, McCain Foods Limited v. J.R. Simplot Company (2025 FC 1078), revolved around whether Simplot’s PEF system—used to pretreat potatoes before cutting—fell within the patent scope claimed by McCain. At the centre of the dispute was the interpretation of the term “high electric field.”

In its judgment, the Court sided with Simplot’s narrower interpretation, concluding that McCain’s patent covered only electric fields in the range of 2 to 200 V/cm, and not the much higher voltages used in modern PEF applications, which can exceed 1,000 V/cm. As a result, Simplot’s use of high-voltage pulsed systems was found not to infringe the patent.

Justice McHaffie noted that adopting McCain’s broader interpretation would render the claims invalid due to overbreadth and inutility. The Court emphasized that McCain had neither tested nor soundly predicted the effects of PEF at the higher voltages and shorter durations that define current commercial PEF systems.

The ruling also addressed the admissibility of expert testimony on common general knowledge (CGK). McCain had challenged Simplot’s technical expert on grounds that he had not interpreted the patent claims directly. The Court rejected this argument, stating that expert evidence on CGK remains admissible and relevant, provided it helps contextualize the invention and the state of the art at the time of filing.

In its findings, the Court stressed that PEF technology differs not only in degree but also in kind from the electric field treatments described in McCain’s patent. The decision pointed to the distinct equipment required, differing technical effects on plant tissue, and the overall technological separation between PEF and earlier methods of reducing cutting resistance in potato processing.

Legal costs of approximately CAD 1.7 million were awarded to Simplot.

This decision marks a significant development in the industrial application of PEF technologies, offering clarity for processors seeking to innovate in non-thermal pretreatment methods. It also underscores the need for precision in patent drafting, especially when protecting or challenging technologies at the frontier of food processing innovation.