Keeping with our food theme in our December blog posts, let’s talk about how we make bread. Traditionally, bread makers used potassium bromate as an oxidizing agent that reacts with other compounds in the bread. It strengthens dough and makes the final bread product bigger, which makes bread makers happy.
But there’s a little problem with potassium bromate: it carries certain health risks when used in food manufacturing. So bakers sought another alternative that would fit the bill. That’s how these baking wars started.
Kim v. The Earthgrains Co., No. 2011-1242 (Fed Cir. Dec. 9, 2011) (Judges Lourie, Bryson, and Moore)
Kim—a food chemist—was granted a patent on a combination of ascorbic acid and a “food acid” that would act as an alternative to potassium bromate during the bread-making process. (Ascorbic acid is also called Vitamin C or L-ascorbic acid. It’s a vitamin found in fruits and vegetables that happens to be soluble in water and can oxidize and convert to the compound DHA.) Here’s an educational video that is chock full of information about this handy compound (added bonus, it features pirates):
Back to the PTO
After the patent issued, Kim put it through a reissue proceeding at the Patent and Trademark Office. She may have wanted to expand the claims to cover a competitor’s products—but the motivation for the reissue filing wasn’t disclosed in the opinion. During reissue, she changed two parts of the claims. One change affected the transitional phrase used at the opening of the claim; she changed it from “consisting essentially of” to “consisting of” (more on this later). The other change narrowed the claimed food acid component of the claim so that it covers compounds that slow down the process by which ascorbic acid converts to DHA during a manufacturing process involving yeast-leavened products. The examiner noted that both claim changes were required to overcome prior art.
A Seven-Year War
After the reissue patent was granted, Kim sued Sara Lee Bakery Group, Inc. for infringement. (The Earthgrains Co. became part of the Sara Lee family.) The district court decided the patent claims were invalid as anticipated by prior art, and the Federal Circuit reversed that decision when it was appealed. After the Federal Circuit sent the case back to the district court, a seven-year patent war ensued.
Kim lost the war. So she filed another appeal at the Federal Circuit.
She didn’t like the district court’s interpretation of certain claim terms or its decision that Sara Lee did not infringe the patent claims by using bromate replacers in the six breads it sold after the reissue patent was granted.
She also appealed the question of whether Sara Lee had intervening rights because of amendments made to the claims during prosecution of the reissue patent. (The intervening rights doctrine limits the damages claim a patentee can make for the time period between the date the original patent and reissue patent claims issue. If the reissue patent claims are substantially different, the patentee can’t get damages for infringement that occurs during that time period.)
No Dough for You
The Federal Circuit interpreted the original and reissued claims in order to determine whether they are substantively the same. It noted that during the second examination, the phrase “consisting essentially of” was replaced with “consisting of,” which is a different transitional phrase commonly used in the first part of patent claims. “Consisting of” excludes any elements, steps, or ingredients not specified in the rest of the claim. In contrast, “consisting essentially of” allows for additional ingredients that do not materially affect the basic aspects and novel properties of the patented invention, and makes the claim broader than one that uses “consisting of.” Unfortunately, she did not address the second claim change during the appeal, which means that she waived any opportunity to get the district court’s decision on intervening rights overturned.
Finally, the court concluded that because there was no evidence showing that Sara Lee’s potassium bromate replacers have the amount of ascorbic acid by weight—per 100 parts flour range—that the patent claims, there was no factual dispute. Since the tablet’s ascorbic acid is oxidized before it is combined with other ingredients that are part of the claimed replacer in Sara Lee’s breads, it’s not known how much of it is present after the tablets are dissolved and oxidation begins.
It sounds like Kim failed to test or find documentation regarding the amount of this claimed ingredient at the correct stage in the process. So this failure of evidence means that Sara Lee walks away with its dough.
Here’s the Federal Circuit’s second opinion in this case.