Novel Food Information - Cluster dextrin®, CCD® (cyclic dextrin, highly branched)

Health Canada has notified Glico Nutrition Co., Ltd. that it has no objection to the sale of Cluster Dextrin®, CCD® (cyclic dextrin, highly branched) as a food ingredient to be added to foods and beverages in Canada. CCD® is intended to be used as a carbohydrate source, totally or partially replacing conventional digestible carbohydrates in a variety of food categories at a level ranging from 3% to 50%. The primary applications are sports drinks, baked goods, cereals, grain products and pasta, milk products, plant protein products, processed fruit and vegetables and their juices, powder applications and others. Some of the foods in which CCD® is intended to be used (for example, fruit juices, chocolate, coffee and tea) have a standard of identity and composition set out in the Food and Drug Regulations (FDR). The standard may not contain a provision for the food to contain cyclic dextrin, highly branched. Therefore, it is recommended to consult with the Canadian Food Inspection Agency to confirm whether standardized foods of interest are, in fact, permitted to contain cyclic dextrin, highly branched.

The Department has reviewed the information provided by Glico Nutrition Co., Ltd. and conducted a comprehensive safety assessment of the addition of CCD® to the Canadian food supply.

Background:

The following provides a summary of the notification from Glico Nutrition Co., Ltd. and the evaluation by Health Canada and contains no confidential business information.

1. Introduction

CCD is a white odourless powder made of at least 80% highly-branched cyclic dextrins with molecular weight ranging from 30,000 to 1,000,000 and an average degree of polymerization of 2,500 glucose units. The short linear chains of the CCD ingredient are composed of α-(1→4)-linked glucose units with branching occurring via α-(1→6) glucosidic bonds, while the ring structure (or cyclic α-glucan moiety) is formed by an α-(1→6) linkage between the terminal glucose of a free chain and a non-terminal glucose in another chain and is composed of 16 to 100 α-linked glucose units. The ingredient also contains less than 3.5% of single glucose molecules, and approximately 10% of other saccharide molecules that are either smaller or larger than the highly-branched cyclic dextrins.

2. Description of the Novel Food/Novel Process

CCD is derived from waxy corn starch through an enzymatic process involving a cyclization reaction. This process, not previously applied to waxy starch, induces a major change in the starch structure. In addition, highly-branched cyclic dextrins do not have a history of safe use as a food. Therefore, CCD is considered a novel food ingredient as detailed in Division 28 of Part B of the FDR, and under this division, the Food Directorate has a legislated responsibility for the pre-market assessment of novel foods and novel food ingredients.

3. Product Development

The starting material for the production of CCD is waxy corn starch, made of 99% of amylopectin, the branched starch component. The manufacturing process of CCD includes two sequential enzymatic reactions using an α-amylase and a branching enzyme. The α-amylase is derived from a non-genetically modified Bacillus subtilis, while the branching enzyme is produced by either a non-genetically modified Geobacillus stearothermophilus or from a genetically-modified Bacillus subtilis containing the branching enzyme gene from Aquifex aeolicus.

In the first step, the α-amylase enzyme is responsible for the hydrolysis of the primary linear chain of amylopectin, resulting in the release of branched dextrins clusters composed of short linear α-(1→4) glucose chains interlinked via α-(1→6) bonds. The high temperature denatures the enzyme during the reaction. During the second enzymatic step, the branching enzyme catalyzes a cyclization reaction via an intramolecular transglycosylation. A terminal reducing glucose unit is transferred from the main α-(1→4) glucose chain to an adjacent acceptor glucose via an α-(1→6) glucosidic bond. The end result is the transformation of the simple starch into a highly branched cyclic dextrin molecule. Sodium hydroxide is added to control the pH during the second enzymatic step. The branching enzyme is subsequently inactivated by reducing the pH with hydrochloric acid and heating the reaction. The mixture is treated with activated carbon to decolourize, and then filtered over diatomaceous earth, perlite, and an ion-exchange resin. The product is evaporated and spray dried.

4. Dietary Exposure

Highly-branched cyclic dextrins are not prevalent or widely identified in conventional foods. However, the concomitant presence of starches with α-amylases and transferases results in the formation of small amounts of cyclic α-glucans. Therefore, there could be minimal background dietary exposure to branched cyclic α-glucans from their natural occurrence in foods.

CCD will be marketed as a source of carbohydrate in replacement of other commercial dextrins. It will be added in conventional beverages and foods at a level ranging from 3% in fruit juices to 50% in dry soups and soup mixes. In sports drinks, it will be added at 10%.

Modelling was conducted by Health Canada to calculate the dietary intake of CCD in the Canadian population using the proposed food uses in conjunction with data from the 2004 Canadian Community Health Survey. Approximately 84% of the total population was identified as consumers of CCD from all proposed food uses. The mean one-day intake of CCD for the Canadian population was estimated to be 21 g per day, with a 95th percentile of 82 g per day. Among the subpopulations considered, boys up to 18 years have the highest mean intake (at 30 g per day) and the highest 95th percentile intake (at 93 g per day).

When the exposure was estimated per kg of body weight, the mean one-day intake for the Canadian population was 385 mg/kg body weight/day, with a 95th percentile of 1435 mg/kg body weight/day. Among the subpopulations considered, infants 2 to 3 years of age had the highest mean and 95th percentile intake, at 1235 and 3290 mg/kg body weight/day respectively.

The exposure estimates were calculated under the assumption that CCD would be substituted for other carbohydrate ingredients in the proposed food categories. Therefore, no impact is expected on the population carbohydrate intakes.

5. Chemical Assessment

Sulphur dioxide is used in obtaining the starch from the corn raw material used to make CCD. There is a specific sulphite labelling requirement, for cases where the general ingredient labelling requirements do not apply, for prepackaged foods that contain 10 ppm or more indirectly added sulphite to alert sulphite-sensitive consumers to the presence of sulphites in these foods. However, the residual level of sulphur dioxide in the finished CCD product is less than 10 ppm. This residual amount of sulphur dioxide in the CCD does not pose a health risk to sulphite-sensitive individuals who may consume foods containing the CCD as an ingredient, and it will not trigger the sulphite labelling requirement.

Sulphur dioxide, sodium hydroxide, hydrochloric acid, the two enzymes, activated carbon, diatomaceous earth, and perlite do not pose a food safety concern when they are used as described to manufacture CCD provided these materials are of a suitable quality for such use, which is a responsibility of the manufacturer to ensure.  The manufacturer is also responsible for using an appropriate ion-exchange resin that does not result in an unsafe food ingredient. Health Canada considers the food-grade quality specifications set out in the most recent edition of the Food Chemicals Codex (FCC), or the most recent specifications established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), to be acceptable as food-grade quality specifications.

Levels of arsenic and lead in CCD were used to estimate the potential contribution to total levels of these substances in foods as a result of the use of CCD as an ingredient. The estimated concentrations were comparable to levels of these contaminants normally seen in foods on the Canadian market in which CCD is proposed for use as an ingredient. The analytical results provided for lead in CCD were also assessed against the maximum level for lead specified in the monograph for dextrin in the current edition of Food Chemicals Codex and found to meet the acceptance criterion of 1 mg/kg. Therefore, from a chemical contaminants perspective, CCD is not expected to pose a safety concern to human health.

6. Microbiological Assessment

Microbial testing results presented for six lots of CCD demonstrated that the manufacturing process resulted in a product that consistently met microbial specifications. In addition, the enzymes used in CCD production (α-amylase and branching enzyme) are inactivated or destroyed during processing, which support their classification as either catalytic reactants or processing aids. Therefore, the manufacturing process of CCD yielded a product of acceptable microbial quality.

Branching enzyme, derived either from a genetically engineered B. subtilis expressing the gene from A. aeolicus or from a non-genetically engineered G. stearothermophilus, is not listed as a food additive in the FDR. However, neither the host nor the donor organisms are known pathogens, and information provided by the petitioner indicated that preparations of branching enzyme are produced in a manner to ensure consistent microbial quality.

The data provided did not raise microbiological concerns regarding the use of CCD as a food ingredient.

7. Nutritional Assessment

CCD is pure carbohydrate and is composed of at least 80% highly-branched cyclic dextrins made of glucose units linked together, approximately 3.5% single glucose molecules, and less than 14% of other saccharide molecules. The glucosidic linkages within CCD are the same as those found in amylopectin, namely, α-(1→4) and α-(1→6) bonds. CCD is completely devoid of vitamins, minerals, fats, proteins, and anti-nutritional factors (phytate).

In vitro experiments conducted with CCD showed that it is digested by human salivary α- amylase to maltose and maltotriose, and is completely hydrolysed to glucose via the action of intestinal digestive enzymes.

Animal and human studies confirmed that the ingredient is efficiently digested to glucose and is well tolerated in humans. Larger CCD molecules with higher degrees of polymerization may escape complete hydrolysis as a result of their size, and will pass into the colon to be subjected to microbial fermentation, as reported for starch components and other dietary α-glucans digested to glucose.

The available evidence support that the digestion of CCD is similar to that of conventional dextrins and starch. Therefore, CCD provides an energy value of 4 kcal/g.

Since the intended use of CCD is to totally or partially replace conventional dextrins in a variety of foods and beverages, the intake of carbohydrates and the energy from carbohydrates are not expected to change and there is no risk of carbohydrate over-consumption.

8. Toxicological Assessment

Toxicological information provided for CCD included an acute oral toxicity test and an in vitro mutagenicity study. Acute, subchronic and chronic oral toxicity studies, genotoxicity studies, and developmental oral toxicity studies on the closely chemically related compound, γ‑cyclodextrin, were also evaluated in support of the assessment of the safety of CCD. None of the toxicology studies with CCD or γ‑cyclodextrin raised concerns. In subchronic and chronic studies, rats were fed diets containing up to 20% γ-cyclodextrin, equivalent to over 10 g/kg bw/day.

A human tolerability study with CCD showed that a one-time 35 g dose was well tolerated by adult males.

An in vitro and an in vivo (mice) metabolic fate study show that CCD is potentially completely digested to glucose, which is an essential constituent in the diet.

CCD is considered not to pose an allergenic risk for the following reasons: there is no protein in the final product, the enzymes used in the manufacturing process have been inactivated and denatured, and there is no sequence identity of those enzymes with any known toxins or allergens.

Overall, there is no health concern from a toxicological perspective with the proposed use of CCD.

9. Labelling

Health Canada and the Canadian Food Inspection Agency (CFIA) share responsibilities in regard to labelling requirements for foods. Health Canada is responsible for policy and standard setting under the Food and Drugs Act and Regulations, whereas CFIA is responsible for enforcement. CFIA also administers and enforces those aspects of the Food and Drugs Act and the Consumer Packaging and Labelling Act that ensure labelling is understandable, truthful and not misleading.

When CCD is added to foods or beverages, its carbohydrate and energy contribution must be included in the amounts reported in the Nutrition Facts table.

With regard to the acceptable common names for CCD in the ingredient list, it was determined in consultation with CFIA that "cyclic dextrin, highly branched" and "highly-branched cyclic dextrin" were appropriate. CFIA also suggested to adding the source (maize/corn) to the above names (i.e., "highly-branched cyclic dextrin from maize").

Conclusion:

Health Canada's review of the information presented in support of the use of Cluster Dextrin®, CCD® (cyclic dextrin, highly branched) as a food ingredient concluded that there are no food safety concerns. It is the continuing responsibility of Glico Nutrition Co., Ltd. to ensure that marketed products are in compliance with all applicable statutory and regulatory requirements.

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.

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

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