Novel Food Information - Whole Algal Protein to be used as alternative protein source in unstandardized foods
Health Canada has notified TerraVia Holdings Inc. that it has no objection to the sale of Whole Algal Protein to be used as alternative protein source in unstandardized foods. The Department conducted a comprehensive assessment of whole algal protein according to its Guidelines for the Safety Assessment of Novel Foods.
The following provides a summary of the notification from TerraVia Holdings Inc. and the evaluation by Heath Canada. This document contains no confidential business information.
TerraVia Holdings Inc., has developed a Whole Algal Protein (WAP) for use as an alternative protein source in unstandardized foods.
WAP is a high protein (≥ 60% protein) algal powder consisting of the milled dried biomass of the microalgae Chlorella protothecoides strain S106. The microalgae are grown by the petitioner in large industrial fermenters under conditions that promote high protein content and allow TerraVia to maintain sanitary conditions.
This microalgae was previously assessed and authorised by the Food Directorate for Whole Algal Flour (WAF), a high-lipid product, for use as a partial replacement for cream, milk, eggs/egg yolk and/or butter/shortening in a variety of foods. In this previous submission, Chlorella protothecoides strain S106 was grown under conditions that promote the synthesis of oils.
The safety assessment performed by Food Directorate evaluators was conducted according to Health Canada's Guidelines for the Safety Assessment of Novel Foods. These Guidelines are based on harmonization efforts with other regulatory authorities and reflect international guidance documents in this area. The assessment considered: the development of WAP; its history of use; the manufacturing and processing methods; its intended use; nutritional composition; microbiological and toxicological information; presence of potential allergens and estimation of its level of consumption by consumers.
The Food Directorate has a legislated responsibility for the pre-market assessment of novel foods and novel food ingredients as detailed in Division 28 of Part B of the Food and Drug Regulations (Novel Foods). Information on the history of food use of Chlorella protothecoidesstrain S106 has not demonstrated that this species of microalga has a history of safe use as food. Therefore, Chlorella protothecoides strain S106 is considered a novel food under the following part of the definition for novel foods:
- “a substance, including a microorganism that does not have a history of safe use as a food.”
2. Product Development
TerraVia obtained C. protothecoides strain S106 from the culture collection maintained at the University of Texas. This strain is designated as UTEX 250 and was originally obtained from the culture collection of the Scottish Association of Marine Science, where it was deposited in the 1950’s as an isolate of C. vulgaris. This original deposit was collected from fresh water in the Netherlands. Other deposits of this strain have been made in Germany and it is also known by the additional designation C. protothecoides var. communis. C. protothecoides Krüger is a synonym for Auxenochlorella protothecoides (Krüger) Kalina & Puncochárová (family Chlorellaceae), which is the name currently accepted taxonomically. All C. protothecoides strains held within the American Type Culture Collection (ATCC) are preserved under Biosafety level I conditions. This indicates that C. protothecoides is not recognized to cause disease in adult humans.
C. protothecoides is characterized as being tolerant to temperatures (28-34 ○C), acidic pH (3.5-4.0) and salt concentrations (3-4%). The petitioner notes that C. protothecoides is the only species known to de-green in the presence of glucose, meaning that it has decreased or no chloroplasts when grown in a high glucose, low nitrogen containing medium. This species has also been shown, under nitrogen depleted conditions, to synthesize and store oil.
WAP is manufactured by fermenting and harvesting cultures of C. protothecoides S106. A pure, clonally isolated culture is initially used to prepare a master seed bank from which working seed vials are prepared. Three samples from the master and each working seed bank are characterized by molecular genotyping to demonstrate that they are genetically identical.
For a production lot, a cryo-preserved working seed vial is thawed and the contents used to inoculate a flask culture, which is transferred into larger flasks at mid-log phase and then to standard, industrial seed fermenters. Throughout the fermentation process, pH, temperature, agitation and aeration rates are controlled, and glucose and nutrients are added. Protein production is favored during fermentation by ensuring that glucose is available as a carbon source and inorganic nitrogen is not limited.
Following fermentation, the cells are washed to remove soluble medium components and concentrated by centrifugation. The separated cells are then inactivated by pasteurization (85 °C, 1 minute). After concentration, the pH is adjusted close to neutral (6.0-8.0) and food-grade antioxidants are added. The biomass, primarily whole cells, is then dried, and optionally milled (to reduce particle size if needed), and packaged. If needed, food grade flow agents may be added to assist processing through drying and packaging; at present the use of such agents is not part of the standard process. The final product, AlgaVia® Protein, is available in quantities of 15 – 25 kg packed in a product bag.
3. Dietary Exposure
The petitioner used United States Department of Agriculture’s What We Eat in America Continuing Survey of Food Intakes by Individuals 2009-2010 to determine the estimated dietary intake of WAP. Based on the proposed food uses, the estimated mean and 90th percentile usual intakes, eaters only, of WAP were 2.3 g/day and 5.5 g/day per person for all ages (1-70+ years old), respectively. The highest intake was observed in the children age group of 1-2 years old with the estimated mean and 90th percentile usual intakes of 94.85 mg/kg bw/day and 189.68 mg/kg bw/day, respectively.
WAP is intended for use as an alternative protein source, similar to soy protein. WAP is not expected to change the overall consumption, by the general population, of any foods to which it is added.
4. Chemical Assessment
The petitioner provided certificates of analysis from three different lots of WAP, which included both specifications and measured concentrations of arsenic, cadmium, lead, and mercury. Data on the concentrations of chromium and cobalt from earlier production lots were also provided. These concentrations were used to estimate the exposure to these contaminants from the use of WAP as an ingredient. Estimates of exposure to these contaminants from the use of WAP were found to have a negligible effect on the background exposure to these contaminants from a typical Canadian diet. The addition of WAP to the foods specified, at the proposed levels of use is not expected to significantly increase the total dietary exposure of Canadians to these trace elements.
The phycotoxins of potential concern to human health are not known to be produced by the Chlorella genus of algae; nevertheless, the petitioner tested WAP for 33 different phycotoxins. None of the phycotoxins were detected above their respective limits of detection. Under the conservative assumption that each phycotoxin was present in WAP at its reported limit of detection, the proposed levels of use of WAP in the foods would not be expected to result in a concern to human health.
5. Microbiological Assessment
C. protothecoides, a synonym for Auxenochlorella protothecoides, is distantly related to members of the genus Chlorella in the phylum Chlorophyta. Evidence provided by the petitioner indicates that while distantly related, C. protothecoides is more closely related to the type strain of C. vulgaris, the most commonly used Chlorella species, than some other strains currently classified as being a member of the C. vulgaris species. This strain, as well as many other strains, is still maintained as C. protothecoides and in the literature C. protothecoides and A. protothecoides are used interchangeably.
Species of Chlorella, including C. protothecoides, are widespread in fresh and salt water, soil and air. As a non-motile, unicellular organism, axenic cultures of this microalga are easily established and replication under optimum conditions tends to be rapid.
In their submission the petitioner noted that, while ubiquitous in nature, algal infections are rare in humans and other animals. A survey of the literature was provided and found only a single case of an opportunistic human infection, which was the result of the exposure of surgical wounds to river water and presented as localised lesions. No reports of human infection due to ingestion were identified. Furthermore, as the WAP is pasteurized at least once during manufacturing, inactivating C. protothecoides, it is not expected that WAP will pose a microbial hazard to consumers.
Specifications for assuring microbial safety were provided by the petitioner. These specifications include testing for total plate count, coliforms, E. coli, Staphyloccoci, Salmonella, Pseudomonasaeruginosa, yeast and mold. All testing is conducted according to AOAC, USP or FDA-BAM methods. Certificates of analysis for three production lots demonstrated compliance with these specifications.
6. Nutritional Assessment
The petitioner provided data on the nutrient composition of WAP, including macronutrients, amino acids, fatty acids, vitamins and minerals. As the composition of Chlorella species is dependent upon the growing conditions during fermentation, the composition of each macronutrient in WAP varies based on the conditions. However, the composition of WAP reported from different batches was within the specifications provided by the petitioner. The protein, carbohydrate, fibre, and total fat content of WAP range from ≥60%, 10-30%, 5-25% and 5-25%, respectively.
The WAP product is composed of amino acids, fatty acids, vitamins and minerals that are expected to be commonly consumed in the typical diet of Canadians and metabolized through normal physiological pathways.
As WAP is proposed as an alternative protein source to soy and animal-based protein, its amino acid composition was compared to that of eggs and soybean. The protein content of WAP is higher than eggs and soybean but all amino acids found in WAP are present in eggs and soybean. WAP is high in the non-essential amino acids glutamic acid and arginine; however, these amino acids are similarly high in soybean when compared as a percent of total protein. In addition, WAP is high in oleic acid and linoleic acid with typical content of each in the range of 30-35% of the total fat. The fatty acid content of palmitic acid, oleic acid, linoleic acid and alpha-linolenic acid represents approximately 93% of the total fat content of WAP. The amino acids and fatty acids in WAP are not expected to present a nutritional concern and are consumed as part of the typical diet of Canadians.
Based on the proposed food uses, the estimated mean and 90th percentile usual intakes, eaters only, of WAP were 2.3 g/day and 5.5 g/day per person, respectively. With the 90th percentile dietary intake for all ages of 5.5 g/day, WAP would provide approximately 3.3 g of protein, 1.4 g of fat, 1.4 g of fibre and 1.7 g of carbohydrate per day based on the highest specification for these nutrients. Furthermore, WAP would not be a major source of vitamins or minerals with the exception of riboflavin, which could contribute approximately 24.5% of the Recommended Dietary Allowance (RDA). Based on the dietary exposure, WAP is not expected to negatively impact the current exposure to protein, fat, fibre, carbohydrate, vitamins and minerals in the Canadian population.
WAP is a mixture of macronutrients, amino acids, fatty acids, vitamins and minerals from the milling of unicellular, eukaryotic green algae C. protothecoides (strain S106). The body’s ability to digest these components is expected to be normal like that of other constituents of food derived from plant materials.
The C. protothecoidesstrain S106 does not produce any known algal toxins (e.g., amnesic shellfish poisoning toxins, paralytic shellfish poisoning toxins, diarrhetic shellfish poisoning toxins, neurotoxic shellfish poisoning toxins and cyanobacterial toxins) as determined by high performance liquid chromatography (HPLC) with fluorescence or mass spectrometry detection.
Pheophorbide A, a plant pigment, can cause photosensitive dermatitis (i.e., skin inflammation that is aggravated by exposure to light) in people who consume natural health products containing Chlorella with high concentrations of pheophorbide A. Pheophorbide A levels in C. protothecoides S106 were below the limit of detection of HPLC (LOD = 0.5 µg/g). This was below the limit prescribed by the
Japanese Public Health Ministry (1.2 mg/g; enforced in 1981). It was concluded that phototoxicity is not expected to be a concern for people consuming WAP.
A standardFootnote 1 90-day subchronic oral toxicity study was performed in rats (10 animals/sex/group) that were provided the WAP at dietary concentrations of 25 000, 50 000 or 100 000 ppm (equivalent to 1177, 2416 and 4805 mg/kg b.w./day in males and 1444, 2700 and 5518 mg/kg b.w./day in females, respectively). The control groups were provided the basal diet with similar levels of dietary protein and fat from casein and lard, respectively. There were no statistically significant, treatment-related effects observed in the standard suite of parameters measured. The NOAEL was calculated to be 4805 mg/kg b.w./day, the highest dose tested in males.
Based on the published literature on Chlorellaproducts (e.g., Chlorella vulgaris, Chlorella pyrenoidosa, etc.) that are currently available in the market as natural health products, it is evident that individuals may initially experience transient gastrointestinal upset (e.g., constipation, mild diarrhea, etc.) when consuming large amounts (e.g., ≥ 1 g/day for adults), but this seems to be a transient effect. In food, excess consumption of WAP is considered unlikely due to its organoleptic properties, since in large amounts it is unpalatable and would be self-limiting.
Young children (1-2 years of age) are the greatest consumers of the foods that could contain the WAP. The 90th percentile of consumers in this subpopulation could be exposed to about 190 mg WAP/kg b.w./day. The WAP was calculated to have a margin of exposure (MOE) that is 25-fold less than the NOAEL reported in the 90-day subchronic oral toxicity study (the highest dose tested in male rats). This margin of exposure is considered sufficient from a safety perspective.
The petitioner conducted a repeat-insult patch test with over 100 human volunteers and used WAP as the test material. Under the conditions of the test, the WAP did not induce contact sensitization and the authors concluded that there was little potential for the WAP to act as an allergen when consumed. However, PTAS is uncertain of the applicability of the repeat-insult skin patch assay for predicting the allergenicity of consumed WAP.
Whole algal flour, algal oils, and more recently WAP, derived from C. protothecoides106 were approved in the United States between 2012 and 2014, for various food uses. Americans have been consuming the C. protothecoides106 proteins in a subset of their foods for over a one year period without reported allergic reaction. Based on this short history of exposure, there is no evidence that products derived from C. protothecoides would produce overt adverse effects in the general population, pregnant women or children.
There is no published information on the allergenicity of Chlorella protothecoides when it is consumed as a food. Based on the published literature on Chlorellaproducts (e.g., Chlorella vulgaris,Chlorella pyrenoidosa, etc.) that are currently available in the market as natural health products, Chlorella can be considered a weak allergen when ingested and can produce dermal reactions in sensitive consumers. Chlorella is not a major allergen and these reactions to Chlorella cease with discontinued exposure.
Health Canada’s review of the information presented in support of the food use of Whole Algal Protein to be used as alternative protein source in unstandardized foods concluded that food products containing WAP do not raise concerns related to safety. It is the continuing responsibility of the manufacturers/sellers/distributors of Whole Algal Protein 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.
(Également disponible en français)
For further information, please contact:
Novel Foods Section
Health Products and Food Branch
Health Canada, PL2204A1
251 Frederick Banting Driveway
Ottawa, Ontario K1A 0K9
- Footnote 1
Standard studies, tests and assays refer to toxicity experiments conducted according to OECD guidelines.
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