Deep Fried And Denied: FCA Dismisses McCain’s Appeal Regarding Claim Construction For French Fry Patent

On April 14, 2026, the Federal Court of Appeal (the FCA) issued its decision in McCain Foods Limited v. J.R. Simplot Company, 2026 FCA 71, dismissing McCain Foods Limited’s (McCain’s) appeal alleging that the Federal Court erred in its construction of the term “high electric field” when concluding that McCain’s Canadian Patent No. 2,412,841 (the ‘841 Patent) was not infringed by its French fry industry competitors, J.R. Simplot Company and Simplot Canada (II) Limited (collectively, Simplot).

The ‘841 Patent claims a process for treating vegetables and fruit to reduce resistance to cutting by applying a “high electric field” to the produce. The lower court’s decision found that the term “high electric field” in the ‘841 Patent refers to electric fields in the range of 2 to 200 volts per centimeter (V/cm). Given that Simplot’s technology used an electric field of 1000 V/cm or more, the lower court concluded that there was no infringement of the ‘841 Patent. The lower court also held that if “high electric field” had been construed to include the electric fields used by Simplot, then certain claims of the ‘841 Patent would be invalid for (i) being broader than the invention made; and (ii) a lack of demonstrated or soundly predicted utility.

In appealing the Federal Court’s decision, McCain argued that the lower court erred in construing the term “high electric field” and was unduly restrictive in applying a rigid numerical limit to its interpretation. However, the FCA found that the lower court conducted an extensive analysis of the common general knowledge relating to electric fields and the language of the claims to come to its interpretation. Furthermore, the FCA rejected McCain’s arguments that the Federal Court improperly limited the ‘841 Patent by relying on preferred embodiments disclosed in the specification. The FCA held that the lower court appropriately considered the embodiments as part of purposive claim construction and reasonably interpreted the claims in light of expert evidence and the common general knowledge. The FCA also found that the lower court did not ignore references to pulsed electric fields, but reasonably concluded that a skilled person would not interpret those references as being included with “high electric fields”.

Overall, the FCA found no reviewable errors in how the Federal Court interpreted the patent and dismissed the appeal.

Summary By: Amy Ariganello