DCT
1:01-cv-03895
Kim v. Earthgrains Co
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Yoon Ja Kim (Illinois) (pro se)
- Defendant: The Earthgrains Company (Missouri)
- Plaintiff’s Counsel: Plaintiff is proceeding pro se.
- Case Identification: 1:01-cv-03895, N.D. Ill., 05/25/2001
- Venue Allegations: Plaintiff alleges venue is proper because Defendant is a Missouri corporation with its principal place of business in St. Louis, Missouri, and is engaged in the transaction of business within the Northern District of Illinois.
- Core Dispute: Plaintiff alleges that Defendant’s "D'ITALIA Italian Bread" and "Buttertop Wheat Bread" infringe a patent related to a chemical composition used as a dough conditioner to replace potassium bromate in yeast-leavened products.
- Technical Context: The technology concerns food science and additives used in commercial baking to improve dough quality, loaf volume, and texture.
- Key Procedural History: The patent-in-suit, Re. 36,355, is a reissue of U.S. Patent No. 5,510,129. The complaint states the reissue was filed to obtain broader claim protection after the original claims were found not to cover a specific formulation. The complaint also details pre-suit correspondence in April-September 2000, in which Plaintiff's attorney notified Defendant of the alleged infringement. An Ex Parte Reexamination Certificate for the Re. 36,355 patent was later issued on March 31, 2009, confirming or amending the asserted claims.
Case Timeline
| Date | Event |
|---|---|
| 1993-11-05 | Re. 36,355 Patent Priority Date |
| 1996-04-23 | Original U.S. Patent No. 5,510,129 Issued |
| 1996-05-14 | Reissue Application for Re. 36,355 Patent Filed |
| 1999-10-26 | Re. 36,355 Patent Issued |
| 2000-03-18 | Earthgrains Co. Acquired Metz Baking Co. |
| 2000-04-13 | Plaintiff's Attorney Sent Infringement Notice Letter |
| 2001-05-25 | Complaint Filed |
| 2009-03-31 | Re. 36,355 Ex Parte Reexamination Certificate Issued |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Reissue Patent No. 36,355 - "Potassium Bromate Replacer Composition"
The Invention Explained
- Problem Addressed: The patent addresses the need in the commercial baking industry for an effective replacement for potassium bromate, a "slow acting oxidant" used to strengthen dough but facing regulatory bans (Re. 36,355, col. 2:10-11, 2:18-25). Common replacements like ascorbic acid were known as "fast acting" oxidants, meaning their strengthening effect was largely dissipated early in the breadmaking process and did not persist through the later proofing and early baking stages where potassium bromate was effective (Re. 36,355, col. 1:35-43).
- The Patented Solution: The invention combines ascorbic acid with a "food acid" (such as citric acid or acetic acid, the primary component of vinegar) and optionally a phosphate (Re. 36,355, Abstract). The patent teaches that the food acid binds with trace metal ions naturally present in flour, which would otherwise rapidly catalyze the oxidation of ascorbic acid. By temporarily sequestering these metal ions, the food acid slows down the oxidation of ascorbic acid, effectively converting it from a fast-acting oxidant to a "slow acting oxidant" that remains functional throughout the entire manufacturing process, mimicking the effect of potassium bromate (Re. 36,355, col. 5:1-34).
- Technical Importance: This approach provided a way to use a natural, widely-accepted ingredient (ascorbic acid) to achieve the functional benefits of a controversial chemical additive (potassium bromate), addressing both product quality and consumer safety concerns (Re. 36,355, col. 2:54-65).
Key Claims at a Glance
The complaint does not specify which claims are asserted, referring generally to infringement of the ’355 Patent. Independent claims 1, 5, 9, and 10, as confirmed or amended by the 2009 Reexamination Certificate, are the likely focus. Claim 5, as amended, is representative of the core invention alleged in the complaint.
- Independent Claim 5 (as amended by Reexamination Certificate): A potassium bromate replacer composition consisting of by weight:
- (a) about 0.001 to 0.03 parts ascorbic acid as an oxidant per 100 parts flour,
- (b) about 0.015 to 0.2 parts food acid per 100 parts flour, said food acid selected from the group consisting of acetic acid, citric acid, fumaric acid, lactic acid, malic acid, oxalic acid, phosphoric acid, succinic acid, tartaric acid, fruit juice, fruit juice concentrate, vinegar, wine, and mixtures thereof and
- (c) flour,
- wherein said food acid is present in an effective amount that slows down oxidation of ascorbic acid to dehydroascorbic acid during a manufacturing process of yeast-leavened products.
III. The Accused Instrumentality
Product Identification
The accused instrumentalities are bread mixes used to produce "D'ITALIA Italian Bread" and "Buttertop Wheat Bread" (Compl. p. 2). The complaint notes "D'ITALIA Italian Bread" is from Metz Baking Co., which was acquired by Defendant Earthgrains, and "Buttertop Wheat Bread" is manufactured by Earthgrains for Nash Finch Co. (Compl. p. 2).
Functionality and Market Context
The complaint alleges the accused products are made using bread mixes containing both vinegar (a source of acetic acid) and ascorbic acid (Compl. p. 4). The infringement theory is based on an analysis of the ingredient lists on the product packaging. Plaintiff infers the relative quantities of these ingredients by their position in the list relative to other ingredients with known typical concentrations, such as calcium propionate (Compl. p. 3). Exhibit A of the complaint provides a sample ingredient list for a different bread product to establish a baseline for calcium propionate concentration (Compl. p. 5). The complaint alleges that the use of this combination reduces production costs by shortening fermentation time (Compl. p. 3).
IV. Analysis of Infringement Allegations
The complaint does not provide a formal claim chart. The following table summarizes the infringement allegations for representative amended Claim 5 based on the narrative in the complaint.
Re. 36,355 Infringement Allegations
| Claim Element (from Independent Claim 5, as amended) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) about 0.001 to 0.03 parts ascorbic acid as an oxidant per 100 parts flour | The accused "D'ITALIA" bread mix allegedly contains 0.0075% to 0.0125% ascorbic acid; the "Buttertop" mix allegedly contains 0.0075% to 0.015% ascorbic acid. | p. 4 | col. 8:50-52 |
| (b) about 0.015 to 0.2 parts food acid per 100 parts flour, said food acid selected from the group consisting of...vinegar... | The accused bread mixes allegedly contain "about 0.2% or less" or "0.2% or less" of vinegar. The "Damages" section alleges a more specific range of 0.125% to 0.15% as acetic acid. | p. 4 | col. 8:53-59 |
| (c) flour | The accused products are bread mixes, which inherently contain flour. The complaint calculates ingredient percentages by weight of flour. | p. 4 | col. 8:59 |
| wherein said food acid is present in an effective amount that slows down oxidation of ascorbic acid... | Plaintiff alleges to have "first discovered that the use of ascorbic acid and food acid enables ascorbic acid to act as a slow acting oxidant." | p. 2, ¶3 | col. 8:66-68 |
Identified Points of Contention
- Evidentiary Questions: The complaint's central assertion of infringement relies on calculating "approximate quantities of ingredients... derived from the ingredient list on the bread package" (Compl. p. 2, ¶1). A primary point of contention will be whether inferring specific percentages from an ingredient list, which only provides relative order by predominance, is sufficient to meet the quantitative limitations of the claims. The defense may argue these allegations are speculative without chemical analysis.
- Scope Questions: What is the scope of the term "about"? The complaint alleges vinegar content of "0.2% or less" (Compl. p. 4), which could be interpreted as touching the upper bound of the claimed range of "about 0.015 to 0.2 parts." The definition of "about" will be critical to determining infringement.
- Technical Questions: Does the amount of vinegar in the accused products actually perform the function required by the "wherein" clause? The defense may contend that even if the accused products contain the claimed ingredients in the claimed amounts, the food acid is not present in an "effective amount that slows down oxidation of ascorbic acid" in its specific formulation or process, thereby not meeting this functional limitation.
V. Key Claim Terms for Construction
The Term: "about"
- Context and Importance: This term appears in the quantitative limitations for both ascorbic acid and food acid in Claim 5. The infringement analysis depends entirely on whether the defendant’s product formulations, which plaintiff estimates to be "about 0.2% or less" for vinegar, fall within the scope of the claimed ranges. Practitioners may focus on this term because its interpretation—whether it provides a narrow or generous range around the stated values—could be dispositive.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification uses general language, stating food acid ranges from "about 0.015 to 0.20 parts" and ascorbic acid from "about 10 ppm to 300 ppm" (Re. 36,355, col. 5:45-49, 5:36-39). The consistent use of "about" for different ingredients may suggest the patentee intended a standard degree of flexibility appropriate for the baking arts.
- Evidence for a Narrower Interpretation: The patent provides specific examples with precise quantities, such as 0.08 parts citric or malic acid (Re. 36,355, col. 6, Table in Example 1). A party could argue that "about" should be construed narrowly in light of these specific working examples.
The Term: "an effective amount that slows down oxidation of ascorbic acid"
- Context and Importance: This functional language in the "wherein" clause of Claim 5 is a critical limitation. Infringement requires not only the presence of the ingredients in the specified amounts but also that the food acid performs this specific function. This term transforms a simple composition claim into one requiring proof of a technical effect.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the general principle that food acids form complexes with metal ions to slow oxidation, suggesting any amount of food acid that achieves this general effect to any measurable degree could be "effective" (Re. 36,355, col. 5:1-9).
- Evidence for a Narrower Interpretation: The patent distinguishes between food acids that form complexes at a fast rate (producing underoxidized dough) and those that form complexes at a slow rate (producing overoxidized dough) (Re. 36,355, col. 7:35-41). A defendant might argue that an "effective amount" must achieve the specific, optimal slowing effect described in the patent to produce "properly oxidized dough," not just any slowing effect.
VI. Other Allegations
- Indirect Infringement: The complaint does not contain sufficient detail for analysis of indirect infringement.
- Willful Infringement: The complaint alleges that Plaintiff's attorney sent a letter to the president of Metz Baking Co. on April 13, 2000, and a subsequent letter to Defendant's counsel on September 6, 2000, informing them of the ’355 Patent and the alleged infringement (Compl. pp. 1-2). These allegations of pre-suit notice may be used to support a claim for willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
This dispute appears to center on fundamental questions of proof and claim scope. The key questions for the court will likely be:
- A core issue will be one of evidentiary sufficiency: Are Plaintiff's infringement allegations, based on inferences drawn from the relative position of ingredients on product packaging, sufficiently particular to state a plausible claim, or are they speculative without quantitative chemical analysis of the accused products?
- A second key question will be one of functional performance: Assuming the presence of the claimed ingredients, does the complaint provide sufficient factual matter to suggest that the food acid in Defendant's bread mixes performs the specific function of "slow[ing] down oxidation of ascorbic acid" as required by the claim's "wherein" clause?
- Finally, the case may turn on a question of definitional scope: How will the term "about" be construed in the context of the claimed ranges, and do the estimated concentrations in the accused products fall within that scope, particularly at the upper boundary for food acid?