Novel Food Information - Wheat Bran Extract as a novel food ingredient

Health Canada has notified Fugeia NV that it has no objection to the addition of wheat bran extract (WBE) as a novel food ingredient at levels of 0.6 to 15% w/w, which provides a maximum of 3.0 g of WBE per serving of food to:

• baked goods and baking mixes, i.e., biscuits, breads and rolls (rye and reduced-calorie white bread), breakfast tarts, cakes, cookies and brownies, crackers (low sodium, regular and sweet);
• grain products and pastas, i.e., meal replacement, granola and cereal bars;
• breakfast cereals, i.e., ready-to-eat cereals;
• pretzels;
• beverages and beverage bases, i.e., carbonated beverages (diet or sugar-free), meal replacement beverages (soy based);
• milk products, i.e. flavoured milk and milk drinks, milk-based meal replacements, yogurt;
• frozen dairy desserts, i.e., ice cream and novelties, frozen yogurt;
• gelatins, puddings and fillings (i.e., custards and puddings);
• jams, jellies and preserves;
• processed fruit and fruit juices, i.e., fruit juices (citrus and non-citrus); and
• processed vegetables and vegetable juices, i.e. tomato juice.

WBE is not permitted to be added to a food for which a standard exists in the Food and Drug Regulations (FDR) unless a provision exists or is made in the standard for WBE as an ingredient.

The Department has reviewed the information provided by Fugeia NV and conducted the safety assessment which included evaluation of the manufacturing process of WBE, the composition and the nutritional safety of WBE, and the potential for WBE to be toxic or cause an allergic reaction.

Background:

The following provides a summary of the notification from Fugeia NV and the evaluation by Health Canada and contains no confidential business information.

1. Introduction

“Wheat Bran Extract” (WBE) is derived from wheat bran, which is the fraction of the wheat grain that consists of the outer fibre-rich tissues surrounding the grain (i.e., pericarp, seed coat, and aleurone). Wheat bran consists of arabinoxylan (19 to 25%), ferulic acid bound to arabinoxylan (~0.3 to 0.5%), β-(1,3)(1,4)-glucan (1 to 3%), cellulose (15 to 25%), starch (17 to 29%), protein (14 to 18%), lignin (about 3%), phytic acid (4 to 5%), and minerals (4 to 7%). The WBE manufacturing process results in the reduction of soluble protein and starch as well as the structural modification of other components. More specifically, the arabinoxylans (AX) in wheat bran are partially depolymerized forming arabinoxylan oligosaccharides (AXOS), the primary constituent of WBE. The average degree of polymerization (avDP) of AXOS in WBE varies from 3 to 8.

WBE is considered a novel ingredient since it is manufactured by a novel process that has not been previously applied to wheat bran and causes the food to undergo a major change in composition, one which is different from the parent material wheat bran. In addition, WBE does not have a history of safe use in Canada, in particular, at the proposed exposure level.

2. Description of the Novel Food

WBE is comprised of ≥90% poly and oligosaccharides consisting of ≥70% arabinoxylan oligosaccharides (AXOS) and ferulic acid bound to arabinoxylan (1 to 3%), ≤2% protein, and ≤ 2% ash. The molecular mass of the AXOS in WBE ranges from 414 to 1,074 Da, compared with a molecular mass of 5000 to > 120,000 Da for the arabinoxylan fractio of wheat bran, of which >90% is insoluble.

Both AXOS and low molecular weight AXs are naturally formed during preparation of bread, beer and cereal following exposure to endoxylanase. However, the AXOS in WBE is different from these compounds with regards to the avDP.

3. Product Development/Formulation

WBE is extracted from wheat bran in a four step process, which the first step is the removal of starch from the wheat bran using amylase. The second step involves the enzymatic depolymerization of the water-unextractable hemicelluloses (i.e., arabinoxylan and β-glucan) using pentosanase. The third step is a purification process using an ion exchange resin treatment that removes a large part of the minerals, organic acids, proteins, and other nitrogenous substances from the liquid fraction. In the fourth and final step, the purified liquid fraction is concentrated and dried. The resulting WBE is an off-white crystalline powder with dry matter content greater than 94%.

WBE is intended to partially or fully replace non-digestible carbohydrate ingredients such as inulin, fructo-oligosaccharides (FOS), polydextrose, resistance starches, polyols and indigestible dextrins in a wide variety of food categories which include baked goods, mixes, beverages, breakfast cereals, desserts, grain products, pastas, milk products, fruits and vegetables including juices and snack foods. WBE is not intended for inclusion in infant formulas or baby foods.

4. Dietary Exposure

Fugeia NV provided estimated intakes of WBE from all of the food categories in which it is intended to be used based on United States’ NHANES 2003-2004 data. Estimates were made using a maximum level of 3.0 g per serving for certain foods and at levels varying from 0.6% to 15% (w/w) and as a partial or full replacement ingredient for all other sources of soluble fibres. In the exposure evaluation, exposure to WBE and its constituents (AXOS, ferulic acid bound AXOS and beta glucans) were considered.

At the 90^th percentile, the WBE intake for the total US population for all persons is estimated to be 9.4 g/person/day and 10.1 g/person/day for users only. Based on an average AXOS content in WBE of 78.6%, an estimate of the 90^th percentile consumption of AXOS for all persons is 7.39 g/person/day and for users only, 7.94 g/person/day. Using Health Canada’s default body weight ranges, an estimate of the 90^th percentile consumption of AXOS amongst all persons ranges from 0.10 to 0.35 g/kg bw/day in the Canadian population and for users only ranges from 0.10 to 0.40 g/kg bw/day.

Arabinoxylans are naturally present in most grain-based foods and beverages, including bread, pastry, pasta, cookies, crackers, pancakes, waffles, ready-to-eat cereals, cereal bars and beer. A substantial amount of ingested arabinoxylan is fermented by colonic microflora to low molecular weight (LMW) arabinoxylans, including AXOS. At the 90^th percentile, the estimated intake of these constituents from the major sources, bread and beer, is approximately 8 g per person per day. The overall effect of the addition of WBE to all food categories may be to double the exposure to AXOS in the Canadian population.

Beta-glucans are found naturally in bran of cereals such as barley, oats, rye and wheat, in the cellulose of plants and the cell walls of yeast, fungi and bacteria. The β-glucans in WBE differ since they are depolymerized and have lower molecular weights than their counterparts in wheat. At the 90^th percentile, the maximum intake of 10.1 g WBE/day (users only) would provide approximately 1.01 g to 1.41 g of β-glucans per day.

Some of the arabinose side chains of the xylanose polymer have ferulic acid moieties attached to them and these moieties constitute 1-3% of WBE, mainly as feruloylated arabinoxylans. The intake of ferulic acid from the consumption of 10.1 g WBE is about 0.15 g/day. A single serving (27.6 g) of wheat bran results in an intake of 0.13 g ferulic acid (0.5% by weight), which is comparable to the intakes from consumption of WBE in its current contemplated application to foods.

5. Chemical Assessment

Wheat bran extract is manufactured using two enzymes, an ion exchange resin treatment process for purification, and acidity regulators for pH adjustment.

The two enzymes, amylase and pentosanase, are used during the first and second steps of the manufacturing process, respectively, and residues of enzyme protein are expected to be largely removed during the purification process. No food safety concerns have been identified with the use of these enzymes or their source organisms.

During the third step of the manufacturing process for WBE, sodium/potassium hydroxide or phosphoric/sulphuric acid are added to the purified liquid fraction, prior to concentration and spray-drying, to adjust pH. From a food safety perspective all four agents are acceptable for this purpose.

Ion exchange resins are commonly used in manufacturing certain food products. In most cases, including their use in manufacturing WBE, there is no requirement for their premarket review by Health Canada.

Onus rests with the food industry to ensure that the use of any substance in food manufacture does not result in a violation of section 4 of the Food and Drugs Act. Section 4 essentially prohibits the sale of an unsafe food. In this regard the manufacturer of WBE should ensure that all substances, including the enzymes, pH adjusting agents, and ion exchange resins, used in manufacturing WBE to be used in food for human consumption are of acceptable quality for use in manufacturing this ingredient.

The concentrations of a number of trace elements, namely lead, arsenic, cadmium, mercury, copper, molybdenum, nickel, chromium and zinc, were measured in WBE and were detected at levels that would not pose a safety concern.

Information in the submission indicated that the elevated temperature employed in the WBE production process may have an impact on carbohydrates during food processing by producing reaction products. Therefore, WBE was also analyzed for furfural, 5-hydroxymethylfurfural and acrylamide. Only furfural was detected at a concentration above its analytical detection limit, but at very low levels. Hence, there was no safety concern with respect to these heat-induced contaminants.

Analytical data for mycotoxins (deoxynivalenol, ochratoxin A, aflatoxins (total), aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, fumonisin B1, fumonisin B2, fumonisins (total), zeralenone, fusariotixin HT-2 and fusariotoxin T-2) in WBE were provided by the petitioner. These data were reviewed by Health Canada and no safety concerns were identified.

6. Microbiological Assessment

Specifications for assuring microbiological safety and data demonstrating compliance with these specifications were provided by the petitioner. As well, specifics on the manufacturing process and the quality control parameters measured during production were evaluated. The source material, production enzymes and the production process of WBE was reviewed and found to be safe.

7. Nutrition

With regard to energy, WBE as a non-digestible carbohydrate provides 2 kcal/g. The protein, fat, vitamin and mineral content of WBE is negligible in comparison to its source material, wheat bran. WBE is not intended to replace wheat bran but to replace the soluble fibre portion only. Hence, the use of WBE will not have significant nutritional impact on the diet of Canadians.

The anti-nutrients found in wheat bran (protease and amylase inhibitors, lectins and phytic acid) are also found in WBE. Lectins derived from wheat have not been shown to have anti-nutritional activity in humans. Because protease and amylase inhibitors are relatively heat labile, they do not pose any anti-nutritional risk in humans as the manufacturing process for WBE includes a heat treatment step. They may be a concern in animal feed or raw and undercooked foods.

Studies assessing the effect of AXOS from wheat bran indicate no significant change in gastric motility or macronutrient digestion.

WBE as a non-digestible carbohydrate is not expected to impact mineral bioavailability. Beta-glucans are polysaccharides of d-glucose monomers linked by β-glycosidic bonds that are resistant to digestion and absorption in the upper gastrointestinal tract. In the colon, they are readily fermented by microflora to produce short chain fatty acids (SCFA) that are metabolized by the colon. Although the change to the avDP of extracted β-glucans from WBE may influence the extent and location of fermentation in the colon, it is not expected to pose any nutritional concerns.

8. Toxicology

Wheat bran, from which WBE is derived, has a history of safe use in Canada. The results of toxicological studies with WBE have shown its metabolic fate resembles that of other non-digestible and fermentable carbohydrates such as inulin, fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS) and cyclodextrin, which are all fermented by colonic bacteria to short chain fatty acids (SCFA).

WBE was not found to be mutagenic in the Ames assay. Rodent feeding studies (90-day study in which rats were fed a diet with 7.5% WBE, preceded by a 14-day dose range-finding study with diets of 5 and 10% WBE) indicate it to be well tolerated and findings (increased cecum weights) are consistent with studies in other high-fibre diets fed to rodents.

Studies in humans also indicate that WBE and AXOS preparations are well-tolerated at levels comparable to the amount in the proposed serving of WBE (3 g). No effects on hematology, clinical chemistry or GI parameters were seen in adults fed up to 10 g WBE /day and in children fed up to 5 g WBE/day for 3 weeks. Adults who consumed 13.9 g of an AXOS preparation (10 g pure AXOS) daily for 3 weeks showed no clinical or hematological effects; the sole gastrointestinal symptom was a mild increase in flatulence.

Given their presumed health benefits, the intake of β-glucans from WBE is not of toxicological concern. On a weight by weight basis, the intake of ferulic acid from WBE is about 3× higher than from an equal amount of wheat bran. However, since ferulic acid is much more poorly absorbed when it is bound to arabinoxylan and much of the ferulic acid in WBE is bound to AXOS, no toxicological concerns are noted. Ferulic acid is much more bioavailable from commonly eaten cereals than it would be from consuming WBE.

Overall, no adverse effects were observed in human studies at levels exceeding the proposed levels of AXOS. This is consistent with the ability of humans to tolerate non-digestible oligosaccharides.

9. Allergenicity and Intolerance

The protein specification for WBE is less than 2%, which is below the level of protein in wheat (10-15%) and wheat bran (14-18%). Adverse reactions to wheat protein may be triggered at levels as low as 2 mg per serving in the most sensitive individuals with wheat allergies. For those with celiac disease, exposure to gluten should be kept below 10 mg per day. The 90^th percentile intake of 10.1 g WBE/day (users only) would result in an estimated 6 mg of wheat protein per serving (10.1 g x 3% per serving x 2% maximum level of protein) and is therefore not suitable for wheat allergic consumers. Individuals with celiac disease are expected to tolerate a food containing WBE. As WBE is not recommended for people with wheat allergy, the presence of “wheat” in WBE should be declared on the label in accordance with the enhanced labelling regulations for food allergens. The use of a gluten-free statement on foods that contain WBE as an ingredient would not be acceptable according to current Health Canada policies.

Conclusion:

Health Canada does not object to the addition of WBE to the list of foods specified herein and to be sold in Canada. Products containing WBE should be labelled accordingly to indicate the presence of wheat and the potential for allergenicity.

No health claims or the acceptability of WBE as a dietary fibre source have been assessed as part of the evaluation.

This Novel Food Information document has been prepared to summarize the opinion regarding the subject product provided by the Food Directorate, Health Products and Food Branch, Health Canada. This opinion is based upon the comprehensive review of information submitted by the petitioner according to the Guidelines for the Safety Assessment of Novel Foods.

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For further information, please contact:

Novel Foods Section
Food Directorate
Health Products and Food Branch
Health Canada, PL2204A1
251 Frederick Banting Driveway
Ottawa, Ontario K1A 0K9
novelfoods-alimentsnouveaux@hc-sc.gc.ca