US 10912321

Analysis of U.S. Patent 10,912,321: A Method for Increasing Poultry Weight During Processing

Washington, D.C. - A comprehensive analysis of U.S. Patent No. 10,912,321, titled "Methods of using peracetic acid to treat poultry in a chill tank during processing," reveals a method aimed at increasing the saleable weight of poultry products by treating carcasses with a specific solution during the chilling process. This patent, issued to Enviro Tech Chemical Services, Inc., has recently been the subject of a significant ruling by the U.S. Court of Appeals for the Federal Circuit.

Patent Overview

• Title: Methods of using peracetic acid to treat poultry in a chill tank during processing
• Assignee: Enviro Tech Chemical Services, Inc.
• Inventors: Michael S. Harvey, Jonathan N. Howarth
• Filing Date: August 16, 2011
• Issue Date: February 9, 2021
• Abstract: The patent discloses methods for treating poultry during processing to increase its weight. These methods can be performed in a chill tank or other reservoirs and utilize either equilibrium or non-equilibrium peracetic acid. The non-equilibrium peracetic acid can be prepared from hydrogen peroxide and a liquid acetyl precursor, such as triacetin. The core of the method involves contacting a poultry carcass with peracetic acid-containing water at a pH of about 6 to about 9.

Litigation Update

Recent legal challenges have impacted the enforceability of this patent. On May 4, 2026, the U.S. Court of Appeals for the Federal Circuit (CAFC) in case number 24-2160, ENVIRO TECH CHEMICAL SERVICES, INC. v. SAFE FOODS CORP., affirmed a lower court's decision that several claims of the '321 patent are invalid due to indefiniteness. The court found that the term "about" in the context of the claimed pH range of "about 7.6 to about 10" was not sufficiently defined by the patent's specification, rendering the claims unclear to a person skilled in the art.

Plain-Language Overview of Independent Claims

An independent claim represents the broadest definition of the invention. An analysis of the independent claims of the '321 patent, prior to the CAFC ruling, reveals the core innovations protected.

Independent Claim 1: This claim outlines a method for increasing the weight of a poultry carcass. The process involves creating a peracetic acid solution in water and then adjusting its pH to a range of approximately 7.6 to 10 using an alkaline source. A poultry carcass is then brought into contact with this pH-adjusted solution. A key aspect is the subsequent monitoring and, if necessary, further adjustment of the solution's pH to maintain it within the specified alkaline range while the carcass is being treated. This controlled alkaline pH environment is presented as the mechanism for increasing the weight of the poultry.

Independent Claim 20: This claim is similar to claim 1 but focuses on a continuous process within a reservoir, such as a chill tank. It specifies providing a peracetic acid solution in the reservoir and adjusting its pH to the alkaline range of about 7.6 to 10. A poultry carcass is then placed in this solution. The claim emphasizes the step of monitoring the pH of the solution while the carcass is in the reservoir and altering it as needed to keep it within the alkaline range. The goal, as with claim 1, is to increase the weight of the poultry carcass.

Independent Claim 34: This claim presents a slight variation on the method. It starts with combining water and an antimicrobial amount of a peracetic acid solution. The pH of this initial mixture is then determined. If the pH is not already within the alkaline range of about 7.6 to 10, it is adjusted accordingly. A poultry carcass is then introduced to the solution. The claim concludes with the requirement to monitor and, if necessary, adjust the pH of the water containing the carcass to maintain the alkaline environment, thereby increasing the carcass's weight.

It is important to note that the CAFC's recent decision on the indefiniteness of the term "about" directly impacts the enforceability of these claims, particularly their specified pH ranges. The court's ruling suggests that the boundaries of the claimed pH ranges were not described with reasonable certainty, a critical requirement for patent validity.

Based on the information provided in the patent text and the summary, the following litigation is known to involve U.S. Patent 10,912,321.

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Known Litigation

1. U.S. Court of Appeals for the Federal Circuit

• Plaintiff-Appellant: ENVIRO TECH CHEMICAL SERVICES, INC.
• Defendant-Appellee: SAFE FOODS CORP.
• Jurisdiction: U.S. Court of Appeals for the Federal Circuit
• Case Number: 24-2160
• Filing Date: The filing date for this appeal is not specified in the provided documents.
• Outcome/Current Status: Decided on May 4, 2026. The court affirmed a lower court's decision, holding that several claims of US patent 10,912,321 are invalid for indefiniteness. The basis for the ruling was that the term "about" in the context of the claimed pH range was not sufficiently defined in the patent's specification. This case is cited in the patent's file wrapper (Source: https://portal.unifiedpatents.com/litigation/Court%20of%20Appeals%20for%20the%20Federal%20Circuit/case/24-2160).

Note: This appellate case implies a preceding case in a lower court (likely a U.S. District Court) where the initial invalidity decision was made. However, details of that specific lower court case, such as its case number, jurisdiction, and filing date, are not provided in the supplied documentation.

Proceedings overview

The USPTO Open Data Portal API indicates no AIA trial proceedings on file for U.S. Patent 10,912,321 as of the most recent ingest. Despite a web search for relevant PTAB activity, no specific Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) proceedings directly related to US Patent 10,912,321 were identified. This means that, based on available public records, the patent has not been subjected to PTAB challenges.

Strategic summary

As no PTAB proceedings have been identified for U.S. Patent 10,912,321, all claims of the patent are currently untested by these specific administrative review processes. There is no estoppel landscape established through PTAB proceedings, meaning a potential defendant would have a full range of prior-art grounds available for an IPR petition, should they choose to file one. The absence of PTAB activity suggests that the patent has not yet faced a direct challenge under AIA trial procedures, which is common for patents that have not been extensively asserted or have not drawn significant attention from defensive aggregators.

Recommended next steps

Since no PTAB activity is currently on file for U.S. Patent 10,912,321, if you are a defendant facing assertion of this patent, consider the following:

• Prior Art Search: Conduct a thorough prior art search to identify any strong invalidity arguments that could form the basis of an IPR or PGR petition.
• Validity Analysis: Engage patent counsel to conduct a detailed validity analysis of the asserted claims, considering both the prior art identified and the recent Federal Circuit ruling regarding indefiniteness of the term "about" for pH ranges. While the CAFC ruling pertains to a different pH range (7.6-10), its reasoning regarding indefiniteness of "about" may be relevant to the claims' broader pH range of "about 6 to about 9."
• PTAB Petition: If strong grounds are identified, filing an IPR or PGR petition could be a viable defense strategy to challenge the patent's validity.

Inventors

• Michael S. Harvey (Enviro Tech Chemical Services Inc.)
• Jonathan N. Howarth (Enviro Tech Chemical Services Inc.)

The inventors were employed by the original assignee, Enviro Tech Chemical Services Inc., at the time of filing, as the application was filed by the company and subsequent assignments confirmed the transfer of inventorship rights to the company.

Original assignee

Enviro Tech Chemical Services Inc. is the original assignee named on the issued patent. This company manufactures and sells peracetic acid (PAA) disinfectants and sanitizers, including "Perasan MP-2," which are used in various industries such as dairy, food, beverage processing, and meat, poultry, and seafood treatment. The patent claims methods of using PAA to treat poultry, directly relating to their primary line of business. Enviro Tech Chemical Services Inc. is currently operating and actively asserting this patent, as evidenced by its involvement in the U.S. Court of Appeals for the Federal Circuit case 24-2160 against Safe Foods Corp.

Assignment timeline

• 2017-03-27 (executed) / recorded 2017-03-31 — Reel 039860/0698

  • Conveyance: Assignment
  • Assignor: HARVEY, MICHAEL S.; HOWARTH, JONATHAN N.
  • Assignee: ENVIRO TECH CHEMICAL SERVICES, INC.
  • Correspondent: RUTH E. CULLEN, CULLEN AND DYKMAN LLP, 100 Quentin Roosevelt Blvd., Garden City, NY 11530. This correspondent also appears on a later assignment for this patent.
  • Context: Formal assignment of inventors' rights to their employer.

• 2019-08-15 (executed) / recorded 2019-08-20 — Reel 049514/0831

  • Conveyance: Assignment
  • Assignor: HARVEY, MICHAEL S.; HOWARTH, JONATHAN N.
  • Assignee: ENVIRO TECH CHEMICAL SERVICES, INC.
  • Correspondent: RUTH E. CULLEN, CULLEN AND DYKMAN LLP, 100 Quentin Roosevelt Blvd., Garden City, NY 11530. This correspondent also appeared on an earlier assignment for this patent.
  • Context: Confirmatory assignment of inventors' rights to their employer.

Timeline diagram

timeline
    title Ownership of US 10912321
    2011 : Application filed by Enviro Tech
    2017 : Inventors assign to Enviro Tech
    2019 : Inventors assign to Enviro Tech
    2021 : Patent Issued to Enviro Tech
    2026 : CAFC affirms claims invalid

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The patent has consistently been assigned to Enviro Tech Chemical Services Inc., an operating company that manufactures and sells products related to the patent's subject matter. The assignments recorded are from the inventors to the company.
2. Known asserter in the chain — not present. Enviro Tech Chemical Services Inc. is an operating company, not a known NPE from public lists. The litigation mentioned in the patent summary indicates Enviro Tech is the plaintiff.
3. Repeat correspondent across the chain — present. Ruth E. Cullen of Cullen and Dykman LLP is listed as the correspondent for both recorded assignments (Reel 039860/0698, recorded 2017-03-31; Reel 049514/0831, recorded 2019-08-20). While the same correspondent handling multiple assignments for the same company is common, and not automatically an NPE signal, it is a noteworthy pattern if the correspondent is otherwise known for NPE work. In this specific chain, it's consistent with an operating company.
4. Cascading transfers — not present. There are only two assignments, both from the inventors to the same operating company, and spaced over two years apart.
5. Pre-litigation transfer — not present. The earliest recorded assignment is 2017-03-31, while the patent issued in 2021. The confirmed litigation activity is from 2026. The assignments occurred years before the patent issued and long before the reported litigation.
6. Bankruptcy fire-sale — not present. There is no indication that Enviro Tech Chemical Services Inc. has undergone bankruptcy proceedings.
7. Privateering — unclear. While Enviro Tech Chemical Services Inc. is an operating company, the nature of its litigation against Safe Foods Corp. would need further investigation (e.g., through SEC filings or court documents) to determine if it aligns with a privateering model where a competitor funds assertion through an NPE. Based solely on the provided patent documents and assignment records, this cannot be confirmed.
8. Defensive aggregator (anti-NPE) — not present. The patent remains with the original operating assignee, Enviro Tech Chemical Services Inc., which is actively asserting it.

Verdict

Operating-company assertion.
The patent's ownership has remained with the original operating company, Enviro Tech Chemical Services Inc., since its application filing. The recorded assignments (Reel 039860/0698, recorded 2017-03-31; Reel 049514/0831, recorded 2019-08-20) are from the inventors to their employer, which is standard practice. Enviro Tech Chemical Services Inc. is a product-shipping entity, and the litigation cited is an assertion by them.

USPTO Assignment Center search for US10912321

Prior Art Analysis for U.S. Patent 10,912,321

This analysis details the most relevant prior art cited against U.S. Patent 10,912,321, focusing on potential anticipation of the patent's claims under 35 U.S.C. § 102. The core of the '321 patent's invention is a method to increase poultry weight by contacting carcasses with peracetic acid (PAA) containing water at an alkaline pH, specifically a range of about 6 to 9, and maintaining that pH.

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1. U.S. Patent No. 6,017,955: "Method for Cleaning and Disinfecting Poultry"

• Full Citation: US 6,017,955 A
• Publication Date: January 25, 2000
• Filing Date: June 17, 1998
• Brief Description: This patent, assigned to Alcide Corporation, describes a method for disinfecting poultry carcasses to reduce microbial contamination. It involves contacting the poultry with an acidic chlorite solution, which can be sprayed or used in a dip tank. The primary focus is on bactericidal efficacy.
• Potential Anticipation: This reference is primarily concerned with disinfection using a different chemical agent (acidic sodium chlorite) and does not teach or suggest using peracetic acid at an alkaline pH for the purpose of increasing poultry weight. While it discloses contacting poultry with a solution in a chill tank, the chemical composition and the technical objective (disinfection vs. weight gain) are different. Therefore, it is unlikely to anticipate the claims of the '321 patent.

2. U.S. Patent No. 6,113,962: "Poultry Treatment"

• Full Citation: US 6,113,962 A
• Publication Date: September 5, 2000
• Filing Date: October 29, 1997
• Brief Description: Assigned to Rhodia Inc., this patent discloses a method for reducing bacteria on poultry carcasses by treating them with an aqueous solution containing a phosphonic acid or its salt, and a source of peroxygen, such as peracetic acid. The described solutions have a pH between 2 and 9.
• Potential Anticipation: This reference is highly relevant. It discloses the use of peracetic acid solutions for treating poultry in a pH range that substantially overlaps with the '321 patent's claimed range of "about 6 to about 9." Specifically, the '962 patent teaches a pH of 2 to 9. The key question for anticipation would be whether the '962 patent also discloses the purpose of increasing the weight of the poultry. The primary stated purpose in the '962 patent is bacterial reduction. However, if weight gain is an inherent result of applying a PAA solution at a pH of 6-9 as taught, an argument for inherent anticipation could be made against the claims of the '321 patent. The '962 patent discloses the key elements of the method—PAA treatment of poultry in an overlapping alkaline pH range.

3. U.S. Patent No. 6,559,111: "Antimicrobial Compositions and Methods of Use"

• Full Citation: US 6,559,111 B1
• Publication Date: May 6, 2003
• Filing Date: August 11, 2000
• Brief Description: This patent, assigned to Ecolab Inc., relates to antimicrobial compositions containing a peroxycarboxylic acid (like PAA), a carboxylic acid, and a specific anionic surfactant. The compositions are intended for use on various surfaces, including food products like poultry, to reduce microbial populations. The patent discusses compositions with a pH range from about 2 to 9.
• Potential Anticipation: Similar to the '962 patent, this reference discloses treating poultry with PAA solutions within a pH range (2 to 9) that overlaps with the '321 patent. The primary objective is antimicrobial efficacy. It does not explicitly mention increasing poultry weight. However, the disclosure of treating poultry with PAA at a potentially alkaline pH makes it a strong piece of prior art. It could potentially anticipate the claims of the '321 patent if the weight gain is an inherent, though unstated, outcome of the disclosed process.

4. U.S. Patent Application Publication No. 2007/0082832: "Biosynthesis of Peracids"

• Full Citation: US 2007/0082832 A1
• Publication Date: April 12, 2007
• Filing Date: May 31, 2006
• Brief Description: This application describes methods for producing peracids using enzymes (perhydrolases) to catalyze the reaction between a substrate (like a carboxylic acid ester) and a peroxygen source. It mentions that the resulting peracid solutions can be used for various applications, including treating food products.
• Potential Anticipation: This reference focuses on the production of peracids rather than their specific application in poultry processing for weight gain. While it broadly mentions treating food, it does not provide specific parameters for poultry chill tanks, such as maintaining an alkaline pH for the purpose of increasing carcass weight. Therefore, it is less likely to directly anticipate the specific method claims of the '321 patent.

5. Bauermeister, L.J. et al., "The Effect of Various Antimicrobials on the Growth of Salmonella and Campylobacter during Poultry Chilling." Poultry Science, Vol. 84, 2005.

• Full Citation: Bauermeister, L.J., J.W. Bowers, J.C. Townsend, and S.F. Bilgili. "The effect of various antimicrobials on the growth of Salmonella and Campylobacter during poultry chilling." Poultry Science 84, no. 7 (2005): 1132-1137.
• Publication Date: July 2005
• Brief Description: This scientific article evaluates the effectiveness of different antimicrobial agents, including peracetic acid, in poultry chill water for controlling Salmonella and Campylobacter. The study mentions testing PAA at various concentrations.
• Potential Anticipation: This publication is relevant as it establishes the use of peracetic acid in poultry chillers, a key environment for the '321 patent's method. The critical factor for anticipation would be the pH conditions under which the PAA was tested. If this paper discloses or suggests using PAA in the chill tank water at a pH between 6 and 9, it would be highly material. Without this specific disclosure, it serves as context for the state of the art but may not directly anticipate the claims, which are distinguished by the specific alkaline pH range and the objective of weight gain.

Obviousness Analysis of U.S. Patent 10,912,321 under 35 U.S.C. § 103

This analysis examines whether the claimed invention in U.S. Patent 10,912,321 would have been obvious to a person having ordinary skill in the art at the time the invention was made.

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Legal Standard and Person of Ordinary Skill in the Art

Under 35 U.S.C. § 103, a patent claim is invalid if the differences between the invention and the prior art are such that the invention as a whole would have been obvious to a person having ordinary skill in the art (PHOSITA). The analysis considers the scope of prior art, the differences between the art and the claims, and the level of ordinary skill.

A PHOSITA for this invention would be a food scientist, microbiologist, or chemical engineer with experience in the poultry processing industry. This person would be familiar with poultry chiller operations, USDA and FSIS regulations for food safety, common antimicrobial agents like peracetic acid (PAA), and the primary economic objectives of poultry processing, including maximizing product yield by weight.

Obviousness Argument

The independent claims of U.S. Patent 10,912,321 are rendered obvious by the combination of prior art that teaches treating poultry with PAA in an alkaline pH range, coupled with the well-established motivation in the poultry industry to increase product weight. The primary combination rendering the claims obvious is U.S. Patent No. 6,113,962 ('962 patent), or alternatively U.S. Patent No. 6,559,111 ('111 patent), in view of the general knowledge and economic drivers within the art.

1. Combination of U.S. Patent No. 6,113,962 and Known Industry Objectives

• Scope of the '962 Patent: As detailed in the prior art analysis, the '962 patent explicitly teaches a method for reducing bacteria on poultry by treating carcasses with a PAA solution. Critically, the '962 patent discloses that these solutions can have a pH "between 2 and 9." This reference directly teaches the central elements of the '321 patent's method: contacting poultry with a PAA solution in an alkaline pH range (6-9) that significantly overlaps with the range claimed in the '321 patent. The primary purpose taught in the '962 patent is disinfection.

• Difference from the '321 Patent: The key difference is the stated objective. The '321 patent claims the method for the purpose of increasing the weight of the poultry, whereas the '962 patent claims it for reducing bacteria. The '321 patent also adds the step of actively monitoring and adjusting the pH to maintain it in the alkaline range.

• Motivation to Combine and Expectation of Success: A PHOSITA would have been motivated to apply the teachings of the '962 patent and arrive at the '321 invention for clear reasons:

  • Known Problem and Obvious to Try: Maximizing the saleable weight of processed poultry is a paramount and long-standing economic goal in the industry. The '321 patent acknowledges this, stating, "it is important for the processors to maximize the weight of the processed products" (Abstract; Column 4, lines 17-20). The '962 patent provides a known, government-approved antimicrobial process using PAA within a broad pH range of 2 to 9. A PHOSITA, seeking to increase product yield, would find it obvious to investigate the effects of varying the operational parameters of this known process. It is a well-understood principle in meat science that alkaline solutions can increase the water-holding capacity of muscle proteins. Therefore, a PHOSITA would have a reasonable expectation that operating the known PAA treatment process at the alkaline end of the disclosed range (pH 6-9) would result in increased water absorption and, consequently, weight gain. This would not be a new invention, but rather the predictable optimization of a known process to achieve a known, highly desirable result.
  • No "Teaching Away": The '962 patent does not teach away from using an alkaline pH; it explicitly includes it in its claimed range. The prior art, therefore, provided a clear path for a skilled person to explore.

• The Element of Maintaining pH: The claimed step of monitoring and adjusting the pH to maintain it within the alkaline range is a routine and obvious element of process control. Once a PHOSITA determines that an alkaline pH provides the dual benefit of disinfection and weight gain, it is a matter of standard engineering practice to implement a control system to monitor and maintain that optimal pH. In a dynamic system like a poultry chiller, where organic matter and fresh water are continuously introduced, such control is not an inventive step but a prerequisite for consistent operation.

2. Supporting Prior Art

• U.S. Patent No. 6,559,111 ('111 patent): This patent serves as an alternative to the '962 patent and strengthens the obviousness argument. It also teaches treating poultry with PAA compositions at a pH of "about 2 to 9" for antimicrobial purposes, reinforcing that the use of PAA in this alkaline range was known in the art.
• Bauermeister, L.J. et al. (2005): This scientific paper confirms that using PAA in poultry chillers was an active and known area of research and application, providing a PHOSITA with the context and knowledge that PAA was a suitable agent for this environment.

Conclusion

The claims of U.S. Patent 10,912,321 would have been obvious to a person of ordinary skill in the art. Prior art, such as the '962 and '111 patents, already taught the core method of treating poultry with PAA in an overlapping alkaline pH range. The motivation to apply this known method for the purpose of weight gain was overwhelmingly strong due to fundamental economic drivers in the poultry industry. The discovery of increased weight was not an unexpected result but a predictable outcome based on established principles of meat science. Therefore, the invention represents the application of a known technique to achieve a predictable and highly desirable result, a combination that falls squarely within the definition of obviousness under 35 U.S.C. § 103.

Based on a detailed analysis of the provided text for U.S. Patent 10,912,321, the following information regarding its prosecution history and term has been determined.

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Patent Term and Expiration Analysis

1. Patent Term Adjustment (PTA)

The patent has been granted a significant Patent Term Adjustment (PTA). The term of a U.S. patent is typically 20 years from the filing date of the earliest U.S. non-provisional application to which benefit is claimed.

• Earliest Priority Filing Date: March 24, 2011 (from application US 13/065,553).
• Calculated Standard Expiration Date: March 24, 2031 (20 years from the priority date).
• Adjusted Expiration Date: The patent documentation explicitly states an "Adjusted expiration" of March 2, 2034.

This adjustment indicates a PTA of 1,074 days, which has been granted by the USPTO to compensate for administrative delays that occurred during the patent's prosecution.

2. Patent Term Extension (PTE)

There is no information within the provided patent documentation to suggest that a Patent Term Extension (PTE) under 35 U.S.C. § 156 has been granted. PTE is typically associated with delays in regulatory review for products like pharmaceuticals and medical devices and is distinct from PTA.

3. Projected Expiration Date

The projected and official expiration date for U.S. Patent 10,912,321 is March 2, 2034. This date includes the full 20-year term calculated from the priority date plus the 1,074 days of awarded Patent Term Adjustment. This expiration is contingent upon the timely payment of all required maintenance fees.

Application and Family Data

1. Continuation and Divisional Applications

U.S. Patent 10,912,321, which issued from application US 13/199,029 (filed August 16, 2011), is part of a larger family of applications. It is a continuing application that claims priority to an earlier patent.

• Parent Application: The application for the '321 patent claims priority to U.S. application US 13/065,553, which was filed on March 24, 2011, and has since issued as US Patent 8,546,449. This relationship makes the '321 patent a continuation of the '449 patent's application.

There is no indication that the application for the '321 patent was a divisional application.

2. Related Family Members

The patent is part of an extensive family of related applications and publications filed in the United States. The legal events listed in the patent file confirm the following related U.S. patent family members:

• Parent Patent: US 8,546,449 (from application US 13/065,553).
• Publication of the '321 Patent Application: US 2012/0244261 A1.
• Other Related Applications and their Publications:
  • Application US 13/507,498 (published as US 2012/0276222 A1).
  • Application US 14/283,138 (published as US 2014/0255520 A1).
  • Application US 14/283,155 (published as US 2014/0255565 A1).

These applications share a common priority claim and are directed to related subject matter, originating from the same inventive work.

Defensive Disclosure and Prior Art Publication

Title: Methods, Systems, and Compositions for Controlled Hydration and Biocidal Treatment of Organic Tissues
Publication Date: April 26, 2026
Disclosure ID: DPD-ETCS-10912321-VAR

Abstract: This document discloses a series of derivative methods, systems, and applications related to the controlled hydration and antimicrobial treatment of porous organic materials, specifically animal tissues, by exposure to pH-modified peroxycarboxylic acid solutions. These disclosures are intended to enter the public domain and serve as prior art for future patent applications in this field. The variations expand upon the core principles of using alkaline peracetic acid (PAA) solutions by introducing alternative components, expanded operational parameters, cross-domain applications, integration with emerging technologies, and fail-safe operational modes.

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Axis 1: Material & Component Substitution

1.1. Method Using Organic Amine Buffers for pH Control

Enabling Description: This method replaces common inorganic alkali sources (e.g., sodium hydroxide) with organic amine-based buffering agents for pH control in a poultry chill tank. A PAA solution is introduced into the chill tank water to a concentration of 20-200 ppm. The pH is then elevated and maintained in the range of 8.0 to 9.5 using a solution of tromethamine (Tris) or a combination of Tris and Bis-Tris. These organic buffers provide a high buffering capacity in the target pH range, offering more stable pH control against the influx of acidic biological matter from carcasses. The system uses an ion-selective electrode specifically calibrated for the chosen amine to monitor buffer concentration, in addition to a standard pH probe. The combination provides superior pH stability, which enhances the predictability of water uptake by muscle tissue.

flowchart TD
    A[Start: Poultry Carcasses Enter] --> B{Chill Tank with PAA Solution};
    B --> C[pH Sensor & Tris Concentration Sensor];
    C --> D{Control Logic Unit};
    D -- pH < 8.0 --> E[Dosing Pump: Tris/Bis-Tris Buffer];
    E --> B;
    D -- pH Stable --> F[Continue Chilling];
    F --> G[End: Hydrated & Disinfected Carcasses Exit];

1.2. In-Situ PAA Generation from Acetylated Polyols

Enabling Description: This variation generates PAA directly within the chill tank system using an acetylated polyol other than triacetin. The system utilizes glycerol diacetate (diacetin) as the acetyl precursor. A side-stream reactor is connected to the main chill tank circulation loop. In this reactor, diacetin is mixed with a 35% hydrogen peroxide solution at a molar ratio of 1:2.2 (diacetin:H2O2). The mixture is activated by passing it through a heated zone (50-60°C) containing a solid acid catalyst (e.g., Amberlyst-15 resin beads) to rapidly form a non-equilibrium PAA solution. This freshly generated PAA solution is then immediately injected back into the main chill tank, where a separate system controls the pH using potassium carbonate. This method allows for a more tunable PAA generation rate and avoids the transport and storage of liquid PAA concentrates.

sequenceDiagram
    participant MainLoop as Main Chill Tank Loop
    participant Reactor as Side-Stream Reactor
    participant Controller
    MainLoop->>Controller: Request PAA
    Controller->>Reactor: Initiate Generation Cycle
    Reactor->>Reactor: Pump Diacetin & H2O2
    Reactor->>Reactor: Pass mixture over Amberlyst-15 Catalyst at 55°C
    Reactor-->>MainLoop: Inject fresh PAA solution
    MainLoop->>MainLoop: Adjust pH with K2CO3

1.3. Water Treatment Using Ozonated Recycled Process Water

Enabling Description: This disclosure describes a method where the makeup water for the chill tank is sourced from pre-treated, recycled process water from other plant operations. The recycled water, high in organic load, first passes through a dissolved air flotation (DAF) unit to remove suspended solids. It is then injected with ozone (O3) at a concentration of 2-5 mg/L in a contact chamber to oxidize remaining organic contaminants and provide primary disinfection. This Ozonated Recycled Process Water (ORPW) is then used as the feed water for the PAA chill tank. The residual ozone catalytically decomposes, but the reduction in overall organic load decreases the demand on the PAA, allowing it to be effective at lower concentrations (15-50 ppm). The pH is subsequently adjusted to 8.5-9.5 with sodium hydroxide for tissue hydration. This integrated approach reduces fresh water consumption and overall chemical costs.

graph LR
    subgraph Water Pre-Treatment
        A(Recycled Process Water) --> B(DAF Unit);
        B --> C(Ozone Contact Chamber);
    end
    subgraph Main Process
        C --> D[PAA Chill Tank];
        E(PAA Concentrate) --> D;
        F(NaOH Solution) --> D;
    end
    G(Poultry In) --> D --> H(Poultry Out);

1.4. Non-Contact Optical pH and ORP Monitoring System

Enabling Description: The system for monitoring the chill tank environment is modified to use non-contact optical sensors, eliminating probe fouling. The internal walls of the chill tank and recirculation pipes are coated with a silicone film impregnated with pH-sensitive (e.g., Bromothymol Blue) and ORP-sensitive (e.g., N,N-diethyl-p-phenylenediamine, DPD) chromophores. An array of external LED emitters and photosensors is positioned outside the transparent sections of the piping. The system measures the change in light absorbance through the film, which correlates directly to pH and Oxidation-Reduction Potential. This provides a real-time, spatially distributed reading of the chemical environment without physical probes, increasing reliability and reducing maintenance in high-fat, high-protein water.

classDiagram
    class OpticalSensorArray {
        +ledEmitterID
        +photoSensorID
        +location
        +readAbsorbance()
    }
    class SensorFilm {
        +chromophoreType : String
        +substrate : String
    }
    class ControlUnit {
        -sensorDataMap
        +calculatepH_ORP()
        +triggerDosingPumps()
    }
    OpticalSensorArray "n" -- "1" ControlUnit : Sends Absorbance Data
    SensorFilm "1" -- "n" OpticalSensorArray : Is read by

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Axis 2: Operational Parameter Expansion

2.1. Hyperbaric Immersion for Rapid Hydration

Enabling Description: This method applies the alkaline PAA treatment in a hyperbaric environment to accelerate water absorption. Poultry carcasses are processed in a batch-wise manner in a pressure vessel rated to 200-500 kPa (2-5 atmospheres). The vessel is filled with a PAA solution (50 ppm) at 2°C, and the pH is adjusted to 9.0. The vessel is then sealed and pressurized with sterile compressed nitrogen gas. The elevated pressure overcomes the natural osmotic resistance of the cell membranes, forcing the alkaline solution into the muscle tissue at an accelerated rate. Residence time is reduced from 45-60 minutes to 10-15 minutes to achieve the same target weight gain, significantly increasing throughput.

stateDiagram-v2
    [*] --> Idle
    Idle --> Filling: Load Carcasses
    Filling --> Pressurizing: Vessel Sealed, Add PAA/Alkali
    Pressurizing --> Holding: Reach 400 kPa
    Holding --> Depressurizing: Timer Expired (12 min)
    Depressurizing --> Draining: Reach Atmospheric Pressure
    Draining --> Idle: Unload Carcasses

2.2. pH Cycling to Maximize Water Retention

Enabling Description: Instead of maintaining a constant alkaline pH, this method employs a programmed pH cycling regimen. Carcasses move through a multi-zone chill tank. In Zone 1, the pH is held at 9.0 for 15 minutes to open the protein structure and induce swelling. In Zone 2, the pH is rapidly dropped to 6.5 by injecting a food-grade acidulant like citric acid. This change in pH alters the isoelectric point of the muscle proteins, trapping the absorbed water more effectively within the protein matrix. In Zone 3, the pH is returned to a moderately alkaline state (pH 8.0) for the final 15 minutes of chilling. This cycling creates an osmotic pumping effect that results in higher final retained water content post-chilling compared to a constant pH process.

flowchart LR
    A(Carcass In) --> B(Zone 1: pH 9.0, 15 min);
    B --> C(Zone 2: pH 6.5, 10 min);
    C --> D(Zone 3: pH 8.0, 15 min);
    D --> E(Carcass Out);
    
    subgraph Chemical Dosing
    F(NaOH Pump) --> B;
    G(Citric Acid Pump) --> C;
    H(NaOH Pump) --> D;
    end

2.3. Aerosolized Alkaline PAA Treatment of Individual Poultry Parts

Enabling Description: This disclosure details the application of the technology at a micro-scale for treating individual, cut-up poultry parts (e.g., tenders, wings, thighs). The parts travel on a conveyor belt through a chamber where an aerosolized solution of alkaline PAA is applied. The solution, containing 500 ppm PAA and buffered to a pH of 9.2 with potassium phosphate, is atomized into 20-50 micron droplets using ultrasonic nebulizers. This aerosol envelops the poultry parts, providing rapid surface disinfection and allowing for moisture absorption through exposed muscle tissue. The process is followed by a flash-chilling tunnel. This method is suitable for products where full immersion is undesirable and allows for precise control of final moisture content.

graph TD
    A[Poultry Parts on Conveyor] --> B[Aerosol Chamber];
    C[Ultrasonic Nebulizer Array] -- 500ppm PAA, pH 9.2 --> B;
    B --> D[Flash-Chilling Tunnel];
    D --> E[Packaging];

---

Axis 3: Cross-Domain Application

3.1. Aerospace: Rehydration System for Long-Duration Mission Foodstuffs

Enabling Description: This system adapts the principle for rehydrating and sterilizing dehydrated protein-based food bricks (e.g., meat, tofu) for astronauts. The food brick is placed in a sealed, flexible pouch. A pre-packaged ampoule containing a sterile, concentrated PAA/Tris-buffer mixture is broken inside the pouch, mixing with injected water. The resulting solution (10 ppm PAA, pH 8.5) rehydrates the food brick. The alkaline pH accelerates water uptake and tenderizes the protein matrix, improving palatability. The low PAA concentration ensures sterility without leaving harmful residuals. The entire process occurs within a contained pouch, minimizing free-floating liquids in a zero-gravity environment.

sequenceDiagram
    participant Astronaut
    participant RehydrationPouch
    participant WaterDispenser
    Astronaut->>RehydrationPouch: Insert Dehydrated Food Brick
    Astronaut->>WaterDispenser: Connect Pouch
    WaterDispenser-->>RehydrationPouch: Inject 150mL Sterile Water
    Astronaut->>RehydrationPouch: Crush internal PAA/Tris Ampoule
    RehydrationPouch->>RehydrationPouch: Solution forms (pH 8.5) and hydrates food

3.2. AgTech: Post-Harvest Turgor Enhancement for Leafy Greens

Enabling Description: This application aims to increase the shelf-life and marketable weight of harvested leafy greens (e.g., spinach, lettuce). Immediately after harvesting, the greens are immersed for 60-90 seconds in a cold water bath (4°C) containing a low concentration of PAA (5 ppm) and buffered to a pH of 8.2 using food-grade potassium bicarbonate. The slightly alkaline condition facilitates water uptake into the plant cells through the stomata, increasing turgor pressure and making the leaves appear crisper and fresher. The PAA provides surface disinfection, reducing spoilage from common agricultural bacteria. This "crisping" process adds 3-5% to the saleable weight and extends shelf stability by 2-3 days.

flowchart TD
    A[Harvested Lettuce] --> B{Immersion Tank};
    B -- Water @ 4°C, 5ppm PAA, pH 8.2 --> B;
    B -- Residence Time: 90s --> C[Dewatering Shaker];
    C --> D[Packaging];

3.3. Textiles: pH-Controlled Fiber Swelling in Leather Tanning

Enabling Description: This method is applied during the "bating" stage of leather production. After dehairing, raw hides are placed in a rotating drum filled with a solution containing 100 ppm PAA and a borax buffer to maintain a pH of 9.0. The alkaline environment causes the collagen fiber bundles within the hide to swell and separate, which is critical for achieving softness in the final product. The PAA serves as a powerful disinfectant to prevent bacterial putrefaction during this sensitive stage. This controlled, antimicrobial swelling allows for deeper and more uniform penetration of subsequent tanning agents, improving the quality and consistency of the finished leather.

graph LR
    A(Raw Hides) --> B(Rotating Drum);
    C(PAA/Borax Solution - pH 9.0) --> B;
    B -- Process Time: 4-6 hours --> D(Rinsing);
    D --> E(Tanning Stage);

---

Axis 4: Integration with Emerging Tech

4.1. AI-Driven Predictive Control of Hydration

Enabling Description: An AI control system optimizes the poultry chilling process in real-time. An input station uses a 3D vision system and hyperspectral imaging to determine the size, weight, and estimated fat/protein ratio of each carcass entering the chill tank. This data is fed to a machine learning model (e.g., a trained neural network) that predicts the optimal pH (within 8.0-9.5), PAA concentration (30-150 ppm), and residence time to achieve a target weight gain with minimal chemical usage. The model continuously adjusts the setpoints for the NaOH and PAA dosing pumps based on the real-time load and organic feedback from in-tank turbidity and ORP sensors.

flowchart TD
    A[Carcass In] --> B(3D & Hyperspectral Scanner);
    B -- Carcass Data --> C(AI Predictive Model);
    D[In-Tank Sensors: pH, ORP, Turbidity] -- Real-time Feedback --> C;
    C -- Optimal Setpoints --> E(Dosing Pump Controllers);
    E -- Control Signals --> F(NaOH & PAA Pumps);
    F --> G{Chill Tank};
    A --> G;
    G --> H[Carcass Out];

4.2. IoT Sensor Mesh for Spatio-Temporal Process Mapping

Enabling Description: A network of 50-100 wireless, battery-powered IoT sensor nodes is deployed throughout the primary chill tank. Each node is encapsulated in a food-safe, neutrally buoyant polymer sphere and contains sensors for pH, temperature, and ORP. The nodes move freely with the water flow. They communicate their readings and location (via low-power acoustic triangulation) to gateway receivers mounted on the tank exterior using the LoRaWAN protocol. The data is aggregated in a cloud platform to generate a real-time 3D map of the tank's chemical and thermal conditions, highlighting areas of poor circulation or insufficient disinfectant concentration. This allows for targeted adjustments to water jets or agitator speeds to ensure process uniformity.

erDiagram
    CHILL_TANK ||--o{ IOT_NODE : contains
    IOT_NODE {
        string nodeID
        float pH
        float temperature
        float ORP
        string location
    }
    GATEWAY ||--|{ IOT_NODE : receives_data_from
    GATEWAY {
        string gatewayID
        string location
    }
    CLOUD_PLATFORM ||--|{ GATEWAY : aggregates_from
    CLOUD_PLATFORM {
        string tankID
        json 3D_map_data
        timestamp lastUpdate
    }

4.3. Blockchain Ledger for Farm-to-Fork Process Verification

Enabling Description: A private blockchain (e.g., Hyperledger Fabric) is used to create an immutable record of the chilling process for each batch of poultry. When a batch enters the chill tank, a new block is initiated. The AI control system acts as an oracle, writing validated data points (e.g., average pH, min/max temperature, residence time, average weight gain) to the blockchain at set intervals. The final data is cryptographically signed. A QR code on the consumer packaging, compliant with the GS1 Digital Link standard, links to a public-facing web interface. Consumers can scan the code to query the blockchain and view the certified processing parameters for that specific batch, ensuring transparency and verifying claims of humane and safe processing.

sequenceDiagram
    participant VisionSystem
    participant AI_Controller
    participant Blockchain
    participant Consumer
    VisionSystem->>AI_Controller: Batch ID and Carcass Data
    AI_Controller->>Blockchain: Initiate New Block (Batch ID)
    loop Every 5 minutes
        AI_Controller->>Blockchain: Write Signed Data (pH, Temp, etc.)
    end
    AI_Controller->>Blockchain: Finalize and Seal Block
    Consumer->>Consumer: Scan QR Code on Package
    Consumer->>Blockchain: Query Batch ID
    Blockchain-->>Consumer: Display Certified Process Data

---

Axis 5: The "Inverse" or Failure Mode

5.1. Limited Functionality "Biocidal Rinse" Mode

Enabling Description: This describes a safe operational mode for periods of system maintenance or sensor failure. In this mode, the automated pH control is disabled. The PAA concentration is elevated to a fixed high level (e.g., 250 ppm) to ensure antimicrobial efficacy across a wider pH range. A slow-release, solid acid buffer (e.g., blocks of sodium bisulfate) is placed in the circulation system to maintain the pH in a slightly acidic range (5.0-5.5). In this state, water absorption by the carcasses is minimal, but FSIS pathogen control standards are still met. The system prioritizes food safety over the economic benefit of weight gain when full process control is not available.

stateDiagram-v2
    state "Normal Operation" as Normal {
        description "pH: 8.5-9.5, PAA: 50ppm"
    }
    state "Limited Functionality Mode" as Limited {
        description "pH: 5.0-5.5, PAA: 250ppm"
    }
    [*] --> Normal
    Normal --> Limited: Sensor Failure OR Manual Override
    Limited --> Normal: System Restored & Calibrated

5.2. Reversible Hydration for Product Specification Targeting

Enabling Description: This method allows for precise targeting of final product weight. First, the carcasses undergo the standard alkaline PAA hydration process (pH 9.0) to achieve maximum weight gain. After exiting the primary chill tank, they pass through a secondary, smaller "finishing chill tank." The water in this second tank contains a neutral pH but is a slightly hypertonic solution, created by adding a food-grade solute such as sodium lactate or potassium phosphate to an osmolarity of 300-400 mOsm/L. This controlled osmotic differential draws a predictable amount of the previously absorbed water out of the tissue. By adjusting the residence time in the finishing tank (3-10 minutes), the final weight can be precisely controlled to meet specific customer or product specifications (e.g., "Max 8% retained water").

flowchart TD
    A[Carcass In] --> B(Primary Chill Tank - pH 9.0);
    B -- Max Hydration --> C(Finishing Chill Tank - Neutral pH, Hypertonic);
    C -- Controlled Dehydration --> D(Dripline);
    D --> E[Final Packaging];

---

Combination Prior Art Scenarios

1. Integration with OPC Unified Architecture (OPC-UA): The entire poultry chilling system, including the PAA/alkali dosing pumps, pH/ORP/temperature sensors (whether optical or electrode-based), and control valves, is disclosed as a system where each component communicates via the open-source OPC-UA standard. The control unit acts as an OPC-UA server, exposing data tags for all process variables (e.g., Tank1.pH, Pump.NaOH.FlowRate). Any plant-wide SCADA or ERP system can act as an OPC-UA client to read and write to these tags, ensuring vendor-agnostic interoperability for process control and data logging.

2. Integration with MQTT for Lightweight Sensor Data Transmission: The IoT sensor mesh described in section 4.2 is implemented using the open-source MQTT (Message Queuing Telemetry Transport) protocol. Each sensor node acts as an MQTT client, publishing its data (e.g., { "nodeID": "A73F", "pH": 8.7, "temp": 1.5 }) to a specific topic (e.g., plant/chiller1/nodes/A73F). A central MQTT broker on the plant network receives these messages and forwards them to subscribers, such as the AI control system and the cloud data platform. This leverages a standard, low-power protocol ideal for wireless, battery-operated devices.

3. Integration with GS1 Digital Link for Supply Chain Traceability: The blockchain verification system described in section 4.3 is combined with the open GS1 Digital Link standard. The QR code on the final product is a valid URI structured as https://brand.example.com/gtin/01234567890123?batch=XYZ987. When a consumer's device resolves this URI, the brand's web service uses the batch number (XYZ987) to query its internal blockchain ledger and presents the immutable processing history for that specific batch in a human-readable format, creating a direct, standardized link between the physical product and its digital record.