U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
Office of Food Additive Safety
August 1, 2002

Dr. Alan Richards
Hayashibara International, Inc.
8670 Wolff Court
Suite 200
Westminster, CO 80031-6953

Re: GRAS Notice No. GRN 000099

Dear Dr. Richards:

The Food and Drug Administration (FDA) is responding to the notice, dated February 13, 2002, that you submitted 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 March 1, 2002, filed it on March 1, 2002, and designated it as GRAS Notice No. GRN 000099.

The subject of the notice is pullulan from Aureobasidium pullulans. The notice informs FDA of the view of Hayashibara International, Inc. (Hayashibara) that pullulan is GRAS, through scientific procedures, for use in food in general, including meat products, for multiple technical effects.

As part of its notice, Hayashibara includes the conclusions and signed opinion of a panel of individuals (Hayashibara's GRAS panel) who evaluated the data and information that are the basis for Hayashibara's GRAS determination. Hayashibara considers the members of its GRAS panel to be qualified by scientific training and experience to evaluate the safety of substances added to food.

Hayashibara describes generally available information about the identity, characteristic properties, and functionality of pullulan. Pullulan (CAS Reg. No. 9057-02-7) is an extracellular polysaccharide excreted by the fungus A. pullulans. It is an alpha-D-glucan consisting predominantly of repeating maltotrioses linked by alpha-1,6-glucosidic bonds. This repeating sequence forms a stair-step-type structure. Occasional maltotetrose units are distributed randomly throughout the polymer. Molecular weights for pullulan range from 8,000 to 2,000,000 daltons depending on the growth conditions of the organism. Hayashibara adjusts the growth conditions of the source fungus to produce pullulan products of particular molecular weights and specifications. These include food grade (designated as PF) and deionized (PI) products with mean molecular weights of 100,000 (PI-10 and PF-10) or 200,000 (PI-20 and PF-20). Pullulan is soluble in hot and cold water and is generally insoluble in organic solvents. Pullulan is non-hygroscopic and non-reducing; it decomposes at 250 to 280 degrees C. Water solutions are stable, viscous, and do not form gels. The viscosity of water solutions of pullulan is proportional to the molecular weight of the pullulan. Pullulan readily forms a film, which is thermally stable, anti-static, and elastic. Pullulan has adhesive properties and is directly compressible under heat with moisture.

Hayashibara describes its methods for production of pullulan. The manufacturing process is conducted under current good manufacturing practices and uses raw materials that comply with food grade specifications. Pullulan is produced during mesophilic fermentation of starch syrup by the fungus A. pullulans. The culture is micro-filtered to remove fungal cells. The cell-free filtrate is heat sterilized and the absence of culturable A. pullulans is confirmed. Filtrates are then decolorized and filtered, yielding a filtrate free of foreign substances. The decolorized filtrate is cooled and deionized with an ion-exchange resin to remove chlorides, proteins and colored substances. The deionized filtrate is evaporated to yield approximately 12 percent solids, then decolorized and filtered again. This filtrate is evaporated to yield a 30 percent concentrate, which is dried, pulverized, and classified with a 1.0 mm diameter screen. Hayashibara provides individual specifications for the two food grade pullulan products (HBC Pullulan PF-20 and PF-10), including a specification for lead content of less than 0.1 milligrams/kilogram.

Hayashibara describes pullulan as closely related to amylopectin, dextrin and maltodextrin, and notes that FDA has affirmed the GRAS status of dextrin (21 CFR 184.1277) and maltodextrin (21 CFR 184.1444) for several uses. Hayashibara notes differences between pullulan and these polyglucoses in the relative proportions of alpha-1,4 and alpha-1,6 bonds, the tertiary structure of the molecule, and the extent and mechanism of degradation in the human gut.

Hayashibara describes published information about the safety of the production microorganism, the fungus A. pullulans. The information they cite describes A. pullulans as ubiquitous in nature, nontoxic and nonpathogenic, and characterizes reports of adverse events associated with A. pullulans as extremely rare, restricted to immunocompromised and other high risk individuals, or due to misidentification of the organism.

Using data derived from pullulan consumption in Japan⁽¹⁾, Hayashibara estimates that the daily intake of pullulan from its general use in food is 9.4 grams per person per day (g/p/d) at the mean and 18.8 g/p/d at the 90th percentile⁽²⁾. Hayashibara considers that intake of pullulan is self-limiting due to its organoleptic properties.

Hayashibara presents published and unpublished information related to the safety of pullulan. Hayashibara discusses the fate of pullulan in the digestive tract, referring to a published study using digestive enzymes in vitro and fecal culture digestion experiments. Based on this study, Hayashibara concludes that salivary enzymes and enzymes in the upper gastrointestinal tract hydrolyze pullulan only to a limited extent. Hayashibara also concludes that bacteria typical of the distal intestinal tract in humans hydrolyze the pullulan further and ferment the hydrolysis products to short chain fatty acids. Hayashibara also describes a published human consumption study that reported no symptoms other than abdominal fullness; analysis of stool samples from test subjects corroborated that colonic bacteria can hydrolyze pullulan completely and ferment the hydrolysis products. Hayashibara cites a published study that concluded that pullulan was not mutagenic in a bacterial system. Hayashibara describes one published chronic study in rats and three unpublished acute toxicological studies (two in mice and one in rats) and reports that none of these studies showed deleterious effects attributable to the consumption of pullulan.

Based on the information provided by Hayashibara, as well as other information available to FDA, the agency has no questions at this time regarding Hayashibara's conclusion that pullulan from A. pullulans 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 pullulan. As always, it is the continuing responsibility of Hayashibara 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, as well as a copy of the information in your notice that conforms to the information in proposed 21 CFR 170.36(c)(1), is available for public review and copying on the homepage of the Office of Food Additive Safety (on the Internet at http://www.cfsan.fda.gov/~lrd/foodadd.html).

Potential labeling issues

Under section 403(a) of the Federal Food, Drug, and Cosmetic Act (FFDCA), a food is misbranded if its labeling is false or misleading in any particular. Section 403(r) of the FFDCA lays out the statutory framework for a health claim. In describing the intended use of pullulan and in describing the information that Hayashibara relies on to conclude that pullulan is GRAS under the conditions of its intended use, Hayashibara raises a potential labeling issue under these labeling provisions of the FFDCA. This labeling issue consists of the description of pullulan as "soluble" fiber. If products that contain pullulan bear any claims about such benefits on the label or in labeling, such claims are the purview of the Office of Nutritional Products, Labeling, and Dietary Supplements (ONPLDS) in the Center for Food Safety and Applied Nutrition (CFSAN). The Office of Food Additive Safety (OFAS) neither consulted with ONPLDS on this labeling issue nor evaluated the information in your notice to determine whether it would support any claims made about pullulan on the label or in labeling.

Use in meat products

During its evaluation of GRN 000099, FDA consulted with the Labeling and Consumer Protection Staff of the Food Safety and Inspection Service (FSIS) of the United States Department of Agriculture (USDA). Under the Federal Meat Inspection Act and the Poultry Products Inspection Act, FSIS is responsible for determining the efficacy and suitability of food ingredients and additives in meat and poultry 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 Hyashibara did not provide data to support the use of pullulan as suitable for use in meat products. FSIS states that it cannot consider Hayashibara's notice complete until Hayashibara provides data to FSIS that establish that the ingredients are being used at the lowest level necessary to achieve the intended technical effects in the specific meat products (i.e., product category/type) to which application is desired.

The Federal meat inspection regulations list specific binding additives for use below 3.5 percent of meat product formulation. FSIS has viewed the use of binders and extenders at levels greater than 3.5 percent as re-characterizing products. If Hayashibara provides data to FSIS establishing suitability and efficacy, FSIS would not object to the use of pullulan as a binder in various non-standardized meat products, provided that pullulan does not exceed 3.5 percent of the product formulation. Currently, there are no allowances for the use of pullulan as a binder in standardized meat products.

FSIS requested that FDA advise Hyashibara to seek regulatory guidance from FSIS, Labeling and Consumer Protection Staff, about the use of pullulan in meat products. Hayashibara should direct such an inquiry to Dr. Robert Post, Director, Labeling and Consumer Protection Staff, Office of Policy, Program Development and Evaluation, Food Safety and Inspection Service, 1400 Independence Ave., S.W., Suite 602, Annex, Washington, DC 20250-3700. The telephone number for his office is (202) 205-0279 and the telefax number is (202) 205-3625.

⁽¹⁾Hayashibara considers that a twenty year history of safe use in Japan as a food ingredient and as a pharmaceutical bulking agent corroborates its view that pullulan would be safe under the conditions of its intended use.

⁽²⁾FDA independently estimated that daily intake of pullulan based on food categories and usage levels provided by Hayashibara would be 10 g/p/d at the mean and 20 g/p/d at the 90th percentile.