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Agency Response Letter GRAS Notice No. GRN 000314

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CFSAN/Office of Food Additive Safety

December 13, 2010

Robert Hibbert
K&L Gates, LLP
1601 K St. NW
Washington, DC 20006

Re: GRAS Notice No. GRN 000314

Dear Mr. Hibbert:

This letter corrects an error in the letter issued to you on August 11, 2010, in response to GRAS Notice No. 000314. In that letter, in the section "Use in Products under USDA Jurisdiction," two paragraphs describing certain aspects of the Food Safety and Inspection Service's (FSIS) views on the suitability of pork protein (the new third and fourth paragraphs) were inadvertently omitted. Also, to reflect a recent change in personnel at the United States Department of Agriculture (USDA), we have updated the contact information for the Risk and Innovations Management Division (RIMD) within FSIS. Below is the corrected version of this letter in its entirety.

The Food and Drug Administration (FDA) is responding to the notice, dated December 22, 2009, that you submitted on behalf of Proteus Industries, Inc. (Proteus) in accordance with the agency’s proposed regulation, proposed 21 CFR 170.36 (62 FR 18938; April 17, 1997; Substances Generally Recognized as Safe (GRAS); the GRAS proposal). FDA received the notice on December 30, 2009, filed it on January 5, 2010, and designated it as GRAS Notice No. GRN 000314.

The subject of the notice is pork protein. The notice informs FDA of the view of Proteus that pork protein is GRAS, through scientific procedures, for use as a water binding agent and coating to increase moistness and reduce volume shrinkage in pork products.(1) As a percent by weight of the final product, pork protein may be applied as a coating at up to 0.8%, as a component of batter at up to 0.14%, and as both at a combined total of up to 0.89%.

Pork protein(2) consists of proteins extracted from pork muscle tissue by acid solubilization. Frozen or fresh trimmings, or mince, obtained from USDA-inspected facilities are homogenized with cold potable water to form a slurry. The slurry is acidified to a pH of 2.8 to 3.2 with citric acid (or similar food-grade acid) to solubilize the muscle protein and stabilize the pH of the solution. Proteus describes the protein, lipid, and phospholipid content of this acid-solubilized pork protein preparation by comparison with raw pork muscle tissue. Proteus states that their measurements indicate full recovery of the protein component, and that the amino acid profile is similar to that of raw pork. Lipid content is reduced by more than two-fold.

The acid-solubilized pork protein preparation is centrifuged, if needed, to reduce or remove fat and other materials, and then pre-filtered. Lastly, the material is subjected to an ultrafiltration process that reduces the acid content, and may also remove moisture and salt. The resulting product is expected to have a moisture content range of 88-98%, and a protein content range of 2-12%.(3) Salt may be added back to the protein solution at a level not to exceed the original tissue salt level. The extract may also be concentrated by evaporation to a protein content of 18%, or spray-dried as a powder.

The extract would be added to fresh or frozen pork using injection, mixing, static soaking, vacuum tumbling, or as a coating prior to deep frying. Proteus considers that use of pork protein above the intended use levels is self-limiting, as this would result in a sour taste.

Proteus provides an example of the use of pork protein. In this example, the use level would be a 10% (raw weight basis) application of an 8% solution, where a 112 gram (g) portion of raw pork cooks to 84 g, and the resultant cooked portion contains 0.9 g of added protein and 0.022 g of citric acid. Proteus cites consumption data from a 2008 publication of the Associated Press describing the 2007 per capita consumption of edible pork muscle as 48.2 pounds (21.9 kg) in the United States, which translates to an average consumption of approximately 0.5 g of added protein and 0.012 g of citric acid per day.(4) Proteus states that the level used in the final product will vary depending on the final concentration of protein in the protein solution.

Proteus states that there is extensive evidence in the peer-reviewed literature demonstrating a consensus on the safety of acid-solubilized proteins from both fish and mammalian tissues, and provides a number of citations of published literature to that effect. Proteus concludes that this evidence supports the firm's determination that the intended use of pork protein is generally recognized as safe.

Use in Products under USDA Jurisdiction

During its evaluation of GRN 000314, FDA consulted with RIMD/FSIS at USDA. Under the Federal Meat Inspection Act, Poultry Products Inspection Act, and the Egg Products Inspection Act, FSIS is responsible for determining the efficacy and suitability of food ingredients in meat, poultry, and egg products as well as prescribing safe conditions of use. Suitability relates to the effectiveness of the ingredient in performing the intended purpose of use and the assurance that the conditions of use will not result in an adulterated product, or one that misleads consumers.

FSIS advised that the agency has no objection to the application of pork protein as a coating or as a marinade, or to its addition to ground pork when the pork protein is used as (a) a water binding agent to retain moisture and/or (b) to block fat in cooked product provided:

  • the pork protein is only used in pork food products where binders are permitted and
  • the ingredient "Pork Protein" is appropriately declared on the label of raw "Pork with Pork Protein" product per Title 9 of the Code of Federal Regulations, Section 317.2(c)(2).

In addition:

  • when used as a marinade or protein coating, the pork protein is not to exceed 0.8% by weight of the final product formulation;
  • when used in the batter only, the pork protein is not to exceed 0.14% by weight of the final product formulation; and
  • when used as both a coating and in the batter, the pork protein is not to exceed 0.89% by weight of the final product formulation.

FSIS notes that the suggested descriptive names of "Pork Protein" and "Concentrated Pork Protein" when the protein concentration is 21% or less or when the protein concentration is greater than 21% respectively appear to be appropriate descriptive terms. However, a final determination would be made when a label is submitted to FSIS for a "Pork with Pork Protein" product.

FSIS also notes that the acid extracts and purifies the muscle protein and stabilizes, but is subsequently decreased during the ultra-filtration process. Proteus Industries, Inc. has shown that their use of ultra-filtration in production of pork protein is expected to not result in the residual of food grade acid exceeding 0.04% and any residual of the food grade acid in the "Pork with Pork Protein" product should be substantially lower than 0.04%. FSIS has no objection to the residual food grade acid at such a low level since it does not provide any additional technical or functional effect in the "Pork with Pork Protein" product and is present at an insignificant amount. FSIS considers that such use is consistent with FDA's labeling definition of a processing aid, Title 21 CFR 101.100(a)(3)(ii). Thus, ingredient labeling of the food grade acid is not required when used in the manner described in GRAS Notification GRN 000314.

FSIS requested that FDA advise Proteus to seek regulatory guidance from RIMD/FSIS about the use of pork protein in meat products. Proteus should direct such an inquiry to Ms. Valeria Jefferson, Research and Innovations Management Division, Office of Policy and Program Development, Food Safety and Inspection Service, United States Department of Agriculture, George Washington Carver Center (GWCC), 5601 Sunnyside Ave., Mailstop 5271, Beltsville, MD 20705-5271.

Section 301(ll) of the Federal Food, Drug, and Cosmetic Act (FFDCA)

The Food and Drug Administration Amendments Act of 2007, that was signed into law on September 27, 2007, amends the FFDCA to, among other things, add section 301(ll). Section 301(ll) of the FFDCA prohibits the introduction or delivery for introduction into interstate commerce of any food that contains a drug approved under section 505 of the FFDCA, a biological product licensed under section 351 of the Public Health Service Act, or a drug or a biological product for which substantial clinical investigations have been instituted and their existence made public, unless one of the exemptions in section 301(ll)(1)-(4) applies. In its review of Proteus’s notice that pork protein is GRAS for its intended uses, FDA did not consider whether section 301(ll) or any of its exemptions apply to foods containing pork protein. Accordingly, this response should not be construed to be a statement that foods that contain pork protein, if introduced or delivered for introduction into interstate commerce, would not violate section 301(ll).


Based on the information provided by Proteus as well as other information available to FDA, the agency has no questions at this time regarding Proteus’s conclusion that pork protein is GRAS under the intended conditions of use. The agency has not, however, made its own determination regarding the GRAS status of the subject use of pork protein. As always, it is the continuing responsibility of Proteus to ensure that food ingredients that the firm markets are safe, and are otherwise in compliance with all applicable legal and regulatory requirements.

In accordance with proposed 21 CFR 170.36(f), a copy of the text of this letter responding to GRN 000314, as well as a copy of the information in this notice that conforms to the information in the GRAS exemption claim (proposed 21 CFR 170.36(c)(1)), is available for public review and copying via the FDA home page at To view or obtain an electronic copy of the text of the letter, follow the hyperlinks from the “Food” topic to the “Food Ingredients and Packaging” section to the “Generally Recognized as Safe (GRAS)” page where the GRAS Inventory is listed.


Mitchell A. Cheeseman, Ph.D.
Acting Director
Office of Food Additive Safety
Center for Food Safety and Applied Nutrition

cc: Ms. Valeria Jefferson
Acting Director
Risk and Innovations Management Division
Office of Policy and Program Development
Food Safety and Inspection Service
George Washington Carver Center (GWCC)
5601 Sunnyside Avenue, Mail STOP 5271
Beltsville, MD 20705-5271

(1)These pork products may be marketed at retail as raw meat, or may be further processed prior to retail sale.

(2)Proteus states that "Concentrated Pork Protein" is an appropriate name when the protein concentration of the extract is greater than 21%, the approximate concentration found in raw pork. FDA did not evaluate this statement.

(3)The acidulant in the final product would be present at approximately 0.06% to 0.2%. FDA calculated these values from data provided in the notice.

(4)FDA calculated these values from data provided in the notice.

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