Agency Response Letter GRAS Notice No. GRN 000646

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CFSAN/Office of Food Additive Safety

October 12, 2016

George A. Burdock, Ph.D.
Burdock Group Consultants
859 Outer Road
Orlando, FL 32814

Re: GRAS Notice No. GRN 000646

Dear Dr. Burdock:

The Food and Drug Administration (FDA) is responding to the notice, dated March 28, 2016, that you submitted on behalf of Southeastern Reduction Company, a Division of South Georgia Pecan Company, 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 April 1, 2016, filed it on May 5, 2016, and designated it as GRAS Notice No. GRN 000646.

The subject of the notice is pecan shell flour (also called pecan shell fiber or dried, finely ground pecan shells). The notice informs FDA of the view of Southeastern Reduction Company that pecan shell flour is GRAS, through scientific procedures, for use as a source of fiber and antioxidants in baked goods and baking mixes; breakfast cereals; confections and frostings; gelatins, puddings and fillings; grain products and pastas; meal replacements; snack foods, soft candy; and sweet sauces at levels ranging from 2 to 10 percent (%).

Our use of "pecan shell flour" in this letter should not be considered an endorsement or recommendation of that term as an appropriate common or usual name for the purpose of declaring the substance in the ingredient statement of foods that contain that ingredient. Title 21 CFR 101.4 states that each ingredient must be declared by its common or usual name. In addition, 21 CFR 102.5 outlines general principles to use when establishing common or usual names for nonstandardized foods. Issues associated with labeling and the appropriate common or usual name of a food are the responsibility of the Office of Nutrition and Food Labeling.

As part of its notice, Southeastern Reduction Company includes the report of a panel of individuals (Southeastern Reduction Company’s GRAS panel) that evaluated the data and information that are the basis for Southeastern Reduction Company's GRAS determination. Southeastern Reduction Company considers the members of its GRAS panel to be qualified by scientific training and experience to evaluate the safety of substances added to food. Southeastern Reduction Company's GRAS panel evaluated the identity, composition, method of production, product specifications, estimates of dietary exposure, as well as published studies supporting the safety of pecan shell flour. Based on this review, Southeastern Reduction Company's GRAS panel concluded that pecan shell flour that meets its established food grade specifications and produced in accordance with current Good Manufacturing Practices (cGMP) is GRAS under the intended conditions of use.

Southeastern Reduction Company provides information on the identity, composition, and method of manufacture for pecan shell flour. Pecan shell flour is a fine, reddish brown powder, predominantly composed of insoluble fiber (cellulose, lignin, and hemicellulose) and small amounts of fat, protein, polyphenols, and proanthocyanidins. It is produced from pecan shells (Carya illinoensis) according to cGMP with no substances added during processing. Pecan nuts are cracked and the meat is removed. Pecan shells are ground into pecan shell flour in a temperature-controlled process.

Southeastern Reduction Company provides specifications for primary and minor components in pecan shell flour as well as limitations for heavy metal residues and microbial contaminants. The specifications include: fiber (65-78%, cellulose + lignin + hemicellulose); polyphenols (3-9%, dry basis); proanthocyanidins (8-18%, dry basis); protein (less than 3%); fat (less than 4.5%); and water (5-10%). Limitations on heavy metal residues include: arsenic (less than 0.5 milligram per kilogram (mg/kg)), mercury (less than 0.5 mg/kg), and lead (less than 0.5 mg/kg). Southeastern Reduction Company provides the results of analyses from five lots that demonstrate that pecan shell flour meets these specifications.

The notifier provides the results of stability tests of pecan shell flour showing that the fiber is stable for up to 12 months in sealed containers at 25 °C and 60% relative humidity and at 40 °C and 75% relative humidity. However, the levels of polyphenols and proanthocyanidins begin to decrease after 6 months under both conditions.

Southeastern Reduction Company provides an estimate of dietary exposure to pecan shell flour from the intended uses. Using food consumption from United States Department of Agriculture's What We Eat in America Continuing Survey of Food Intakes by Individuals (2011-2012) and a body weight of 60 kg, the estimated dietary exposure for users only is 5,020 mg per person per day (mg/p/d) (83.7 mg/kg body weight (bw)/d) at the mean and is 9,920 mg/p/d (165.3 mg/kg bw/d) at the 90th percentile.

The notifier also provides a combined dietary exposure to pecan shell flour by combining the dietary exposures from the current use as a flavor ingredient in meat products[1] and from the proposed uses. The notifier estimates the cumulative dietary exposure to pecan shell flour as 5,177 mg/day (86.3 mg/kg bw/d) at the mean and as 10,223 mg/d (170.6 mg/kg bw/d) at the 90th percentile. The notifier notes that this is a conservative estimate of exposure, as it is unlikely that people will consume all of the pecan shell flour-containing products at the 90th percentile levels of intake.

Southeastern Reduction Company discusses data and information supporting the safety of pecan shell flour. Southeastern Reduction Company discusses the metabolic fate of its major constituents, cellulose, hemicellulose and lignin. Southeastern states that these components are resistant to digestion by enzymes present in the human stomach and will pass through the stomach along with indigestible fiber from other sources. Studies in humans have shown that hemicellulose and cellulose are broken down in the large intestine via fermentation by cellulolytic bacteria. Products of microbial fermentation of fiber include carbon dioxide, methane, hydrogen, and short-chain fatty acids (primarily acetate, propionate, and butyrate). The minor amounts of proanthocyanidins present in the pecan shell flour are poorly absorbed in the gut due to their polymeric nature and high molecular weights.

Southeastern Reduction Company describes a published 13-week oral toxicity study in which Sprague Dawley rats were administered pecan shell flour up to a target exposure of 10,741 mg/kg bw/d. The results of the study show no adverse clinical signs or functional changes nor any toxicologically relevant changes in hematology, clinical chemistry, urinalysis parameters, or organ weights in treated rats. Southeastern Reduction Company states that the authors reported a no observed adverse effect level (NOAEL) of 9,948 mg/kg bw/d in male rats and 11,083 mg/kg bw/d in female rats (the highest doses administered).

Southeastern Reduction Company reports that pecan shell flour was non-mutagenic in a bacterial reverse mutation test and non-clastogenic in a mouse peripheral blood micronucleus test.

Based on the available data and information, Southeastern Reduction Company concludes that pecan shell flour is GRAS under the intended conditions of use.

Allergen Labeling

The Federal Food, Drug, and Cosmetic Act (FD&C Act) requires that the label of a food that is or contains an ingredient that bears or contains a “major food allergen” declare the presence of the allergen (section 403(w)). The FD&C Act defines a “major food allergen” as one of eight foods or food groups (i.e., milk, eggs, fish, Crustacean shellfish, tree nuts, peanuts, wheat, and soybeans) or a food ingredient that contains protein derived from one of those foods. Pecan shell flour may require labeling under the FD&C Act, because it may contain protein derived from pecans, a tree nut. Questions about the submission of petitions or notifications for exemptions from food allergen labeling requirements should be directed to the Division of Biotechnology and GRAS Notice Review in the Office of Food Additive Safety. However, questions about food labeling in general should be directed to the Office of Nutrition and Food Labeling.

Standards of Identity

In the notice, Southeastern Reduction Company states its intention to use pecan shell flour in several food categories, including foods for which standards of identity exist, located in Title 21 of the Code of Federal Regulations (CFR). We note that an ingredient that is lawfully added to food products may be used in a standardized food only if it is permitted by the applicable standard of identity.

Potential Requirement for a Color Additive Petition

In its notice, Southeastern Reduction Company describes pecan shell flour as reddish brown. As such, the use of pecan shell flour in food products may constitute the use of a color additive under section 201(t)(1) of the FD&C Act and FDA’s implementing regulations in 21 CFR Part 70. Under section 201(t)(1) and 21 CFR 70.3(f), the term color additive means a material that is a dye, pigment, or other substance made by a process of synthesis or similar artifice, or extracted, isolated, or otherwise derived from a vegetable, animal, mineral, or other source, and that is capable (alone or through reaction with another substance) of imparting color when added or applied to a food; except that such term does not include any material which the Secretary,[2] by regulation, determines is used (or intended to be used) solely for a purpose or purposes other than coloring. Under 21 CFR 70.3(g), a material that otherwise meets the definition of color additive can be exempt from that definition on the basis that it is used or intended to be used solely for a purpose or purposes other than coloring, as long as the material is used in a way that any color imparted is clearly unimportant insofar as the appearance, value, marketability, or consumer acceptability is concerned. Given the construct of section 201(t)(1) of the FD&C Act and 21 CFR 70.3(f) and (g), the use of a substance that is capable of imparting color may constitute use as a color additive in addition to use as a food additive or GRAS substance. For example, beta-carotene is both approved for use as a color additive (21 CFR 73.95) and affirmed as GRAS for use as a nutrient supplement (21 CFR 184.1245); in some food products, beta-carotene is used for both purposes. Importantly, if the use of pecan shell flour constitutes use as a color additive within the meaning of section 201(t)(1) of the FD&C Act and FDA’s implementing regulations in 21 CFR 70.3(f) and (g), section 721(a) of the FD&C Act requires premarket review and approval of that use by FDA. Under section 402(c) of the FD&C Act, a food product that contains an unapproved color additive would be deemed adulterated.[3]

In its notice, Southeastern Reduction Company states that the addition of pecan shell flour is intended to be used solely for purposes other than coloring, and any color imparted is unimportant insofar as the appearance, value, marketability, or consumer acceptability is concerned. Importantly, FDA's response to GRN 000646 does not include any comment by FDA about Southeastern Reduction Company’s view of this issue. If, after receipt of this letter, Southeastern Reduction Company has any specific questions about this issue, we recommend that Southeastern Reduction Company contact the Division of Petition Review in the Office of Food Additive Safety.

Section 301(ll) of the FD&C Act

Section 301(ll) of the FD&C Act prohibits the introduction or delivery for introduction into interstate commerce of any food that contains a drug approved under section 505 of the FD&C Act, 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 Southeastern Reduction Company’s notice that pecan shell flour is GRAS for the intended uses, FDA did not consider whether section 301(ll) or any of its exemptions apply to foods containing pecan shell flour. Accordingly, this response should not be construed to be a statement that foods that contain pecan shell flour, if introduced or delivered for introduction into interstate commerce, would not violate section 301(ll).


Based on the information provided by Southeastern Reduction Company, as well as other information available to FDA, the agency has no questions at this time regarding Southeastern Reduction Company’s conclusion that pecan shell flour 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 pecan shell flour. As always, it is the continuing responsibility of Southeastern Reduction Company 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 000646, 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 at


Dennis M. Keefe, Ph.D.
Office of Food Additive Safety
Center for Food Safety and Applied Nutrition


[1]The Flavor and Extract Manufacturers Association’s Expert Panel evaluated the safety of pecan shell flour for use in meat products in GRAS Flavoring Substances 23 (Waddell, W. J., et al. (2007). Food Technology 61 (8): 22-49).

[2]The Secretary of the Department of Health and Human Services.

[3]We note that section 721(b)(4) of the FD&C Act provides that a color additive shall be deemed to be safe and suitable for the purpose of listing under section 721(b) of the FD&C Act while there is in effect a published finding of the Secretary declaring that the substance is exempt from the definition of a food additive because of its being generally recognized by qualified experts as safe for its intended use as provided in section 201(s) of the FD&C Act. Importantly, FDA’s response to GRN 000646 does not constitute a finding of the Secretary within the meaning of section 721(b)(4) of the FD&C Act.

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