1. Introduction
The FSA and FSS have undertaken a safety assessment for the extension of use of sodium alginate (E 401) as a coating material in entire fresh fruit and vegetables under the common authorisation procedure for food additives, food enzymes and food flavourings legislation, assimilated Regulation 1331/2008. To support the safety assessment by FSA and FSS, the Joint Expert Group on Additives, Enzymes and other regulated products (AEJEG) provided risk assessment advice to the FSA and FSS outlined in this safety advice document.
The dossier was evaluated in line with Article 3 of assimilated Regulation 1331/2008, and has considered the aspects of the food additive and its modification of use. This, and the guidance put in place by EFSA for food additive applications, has formed the basis and structure for the assessment (EFSA, 2012). This assessment has considered the extension of use of the food additive.
With thanks to the members of the AEJEG who provided advice during the course of the assessment who were: Dr Allain Bueno, Dr Claude Lambré, Dr Martin Rose, Dr Olwenn Martin, Professor Qasim Chaudhry and Dr Claire Stephenson.
Information regarding the identity of the substance including existing and proposed specifications were provided. In addition, information on the manufacturing process, stability of the substance, fate in food, existing authorisations and risk assessments, and biological and toxicological data were provided. This information was considered satisfactory. The Applicant did not provide a dietary exposure assessment for E 401 as they stated that it is ‘not expected that sodium alginate would migrate to the internal edible part of the peel, and that due to the specific foods they have listed as part of the application (citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranates) the additive would still very unlikely be consumed directly from the peel.’
It was concluded that sufficient information had been provided to allow for an evaluation of the proposal for modification of the conditions of use of sodium alginate to the surface of entire fresh fruit and vegetables, as a coating to preserve them.
Following the final review by the AEJEG in July 2022, the AEJEG advised that no risk to health will be presented from this extension of use of E 401 on the basis that the additive is considered of low toxicological concern, as indicated by EFSA’s decision that a numerical ADI was not required.
This document outlines the conclusions of the AEJEG assessment on the safety of the extension of use of the sodium alginate (E 401) as a coating material in entire fresh fruit and vegetables (citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranates) at quantum satis. Products included in this assessment are shown in Table 1. This assessment was reviewed by the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) in June 2024.
2. Assessment
2.1. Identity and characterisation
In nature, alginates are hydrocolloids, occurring as salts that form part of the cell wall of brown algae. These compounds, in calcium, magnesium or sodium salt forms, can represent up to 40% of the dry weight of these organisms (Avendaño-Romero et al., 2013). Alginate occurs as an anionic polyelectrolyte with a backbone of (1–4) linked β-D-mannuronic acid (M units) and α-L-guluronic acid (G units). It can form irregular patterns of GG, MG, and MM blocks. Among the organic salts of alginic acid, sodium alginate has been widely researched as a coating material to preserve fruit and vegetable products and has proven to be effective and safe (Guo et al., 2020; Nair et al., 2020; Senturk Parreidt et al., 2018).
The Applicant has provided information on the main identifiers of monomeric sodium alginate as well as its physiochemical properties (Tables 2 and 3).
2.2. Specifications
The specifications for sodium alginate (E 401) are defined in the assimilated Regulation 231/2012 and in the JECFA Combined Compendium of Food Additive Specifications (Joint FAO/WHO expert Committee on Food Additives, 2006).
2.3. Manufacturing process
The Applicant stated that the process of obtaining sodium alginate involves extraction from natural raw material (brown algae) to synthesis using chemical methods. The process begins with the extraction of the alginate salts in the algae with a hot solution of sodium carbonate (alkali). From the previous extraction process, an aqueous substance that contains cellulose results. This solution is diluted, and diatomaceous earth is added to facilitate cellulose separation by filtration. The next step is precipitation of alginic acid or calcium alginate by adding an acid or calcium chloride. Both precipitates are used for the synthesis of sodium alginate by adding sodium carbonate (FAO, 2021).
With regards to the additive relative to this application, the Applicant stated that manufacture of the consumed additive is carried out by a ‘world-renowned company such as Kimica Corporation’ (Japan origin – Global Kimica website). The Applicant provided the technical specifications for the AEJEGs consideration.
They further stated that the additive is purchased through a distribution following quality protocols, by the company Bio Natural Solutions SAC with manufacture of coatings in Peru and with R&D headquarters in the United Kingdom as BNS Worldwide LTD. The production of the coating complies with all the protocols of Good Manufacturing Practices through physical processes of mixing the sodium alginate in water and subsequent homogenisation with the other declared inputs, in a single line for this purpose.
The AEJEG was satisfied that the specifications of E 401 relevant to the current application were compliant with assimilated Regulation 231/2012.
The Committee on Toxicity noted that commercial sodium alginate is a polymer, with a typical average molecular weight of 10,000 - 600,000 (JECFA, 2006)).
2.4. Methods of analysis in food
The Applicant stated that HPLC is commonly used when developing methods for the analysis of sodium alginate in food. Kim et al. (2006) describes an HPLC method using an MCI gel column and deionised water as mobile phase. Separation of sodium alginate was achieved within 15 minutes. Correlation for the standard curve was higher than 0.999 in the 0.1%-2% range, with a limit of detection of 0.005%. This methodology was successfully used in sodium alginate analysis of cereals, chocolate and kelp.
2.5. Composition of the coating mixture
The Applicant provided confidential information regarding the composition of the coating. The AEJEG were satisfied with the information received on the composition of the natural coating mixture used.
2.6. Mode of application of the coating
The form of application in fresh fruits is by spraying a dose of 1 litre of coating per tonne of fruit, that is 1 ml of coating for each kg of fruit treated.
2.7. Case of need
The Applicant provided an overview of the technological need for the use of sodium alginate (E 401) as a coating agent in certain fruits and vegetables. They stated that the additive acts as a film-forming agent that is applied to the surface of fruits and vegetables, which acts as a physical barrier to oxygen and moisture, reducing transpiration and respiration of those fruits and vegetables. As a result, physiological degradation reactions are reduced, which helps to preserve the post-harvest and nutritional quality of fruits and vegetables. Therefore, the edible film allows a better and more durable preservation of those fruits and vegetables and ultimately reduces food waste. The use of sodium alginate (E 401) as a covering agent helps to maintain quality of fresh fruit and vegetables post-harvest prior to consumption by increasing the shelf-life, thus facilitating the availability and increasing the access to market of fresh fruit and vegetables.
2.8. Research on sodium alginate-based coatings for fruits and vegetables
The Applicant listed a number of studies where surface treatment with sodium alginate has been used, as a matrix to apply active ingredients, in order to prevent phytopathogens, preserve the organoleptic properties of foods (e.g. in cinnamon), protect bioactive compounds and prevent water loss in sweet cherries, mangoes, strawberries and cantaloupes and also as a ‘suitable material for nanotechnology applied to postharvest horticultural products’. In these studies, sodium alginate had been used either alone or in a mixture at levels ranging from 1% to 5%.
Based on the data presented in this section, the Applicant noted that ‘Scientific literature shows the viability of sodium alginate as an effective, ecological and innocuous material for the post-harvest treatment of horticultural products. Formulations with the best effects contain a concentration between 1%-3% sodium alginate, commonly added with another active compound of natural origin. For this reason, the coating made from sodium alginate is intended for external treatment as a surface protector for citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranate because it is not expected to migrate to the internal edible part of the fruit. The treatment on fruits of which the peels are usually not consumed is not likely to have an effect on human health.’
Finally, the Applicant noted that the coating would improve the conservation conditions of fruits by improving the quality of imported agricultural products, lead to food loss reduction and that natural products such as sodium alginate from a renewable source are encouraged.
2.9. Existing Authorisations and Risk Assessments
Sodium alginate has been evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA, 1993) with an acceptable daily intake (ADI) ‘not specified’. Following an evaluation of sodium alginate in 1994 by the Scientific Committee for Food (SCF, 1994) they adopted the JECFA provision for an unspecified ADI (section 3.3 in SCF (1994)). This was based on the fact that sodium alginate and its salts were found to be not digested, staying intact, and therefore not absorbed. No adverse effects were observed in a subchronic study in rodents at 13,500 mg/kg bw/d of sodium alginate (no further details on species/duration of study were provided by the Applicant) and there were no concerns over the genotoxicity or carcinogenicity of sodium alginate (tested up to 37,500 mg/kg bw/d in mice) (SCF, 1994).
In 2017, the EFSA ANS Panel re-evaluated alginic acid and its sodium, potassium, ammonium and calcium salts (E 400–E 404) when used as food additives. The Panel concluded that there was no need for a numerical ADI for alginic acid and its salts (E 400, E 401, E 402, E 403 and E 404), and that there was no safety concern at the level of the refined exposure assessment for the reported uses of alginic acid and its salts (E 400, E 401, E 402, E 403 and E 404) as food additives (EFSA ANS Panel, 2017).
The FEEDAP panel (EFSA panel on additives and products or substances used in animal feed) also concluded that there was no need for an ADI for alginic acid and its salts (EFSA FEEDAP Panel, 2017).
Alginates are currently listed as ‘allowed synthetics’ in section 205.605 (b) in the USDA organic regulations (USDA National Organic Program, 2014). Alginates do not appear in the Organic Food Production Act.
Other approvals include:
The Canadian Organic Regime (alginates (alginic acid, sodium alginate, and potassium alginate)) in the section titled ‘Non-Organic Ingredients Classified as Food Additives’, of the Systems Allowed Substances List. of organic production (Canadian General Standards Board, 2011).
-
Codex Alimentarius Commission (2014): Only potassium (E 402) and sodium (E 401) alginates are listed as permitted food additives in Table 3.1 as an ingredient of non-agricultural origin in the Commission’s Guidelines for the Production, Processing, Labelling and Marketing of Organically Produced Foods.
-
EC No 834/2007 and 889/2008: Alginates (E 401-E 405) are included in the list of food additives allowed for use as thickeners and stabilizers (E 400 –E 499). Alginates are classified as non-agricultural in the EU Organic Regulations (assimilated Regulation No 889/2008). Sodium alginate (E 401) is listed as an approved food additive for use in certain raw fruits and vegetables in an amendment to Annex II of Commission Regulation (EC) No 969/2014.
-
The Japan Agricultural Standard (JAS) for organic processed foods identifies sodium alginate as a limited permitted food additive for use only in processed foods of plant origin, INS number 401 (The Japanese Organic Standard, 2005).
-
The International Federation of Organic Agriculture Movements recognises sodium and potassium alginate as approved additives for use in processed organic products without annotation (IFOAM, 2014).
2.10. Proposed Use Levels
Currently, sodium alginate (E 401) is approved for use in food in a number of food categories. The Applicant has provided information on the current authorisations and the Maximum Permitted Levels (MPLs), per assimilated Regulation 1333/2008 shown in Table 4:
The Applicant noted that when used as a coating material for an edible surface treatment of fresh fruit, E 401 prevents moisture loss, which in turn protects the quality, extends the shelf life and ultimately reduced food waste.
Additional current authorisations and the Maximum Permitted Levels (MPLs), per assimilated law Regulation (EC) No 1333/2008 have been presented below in Table 5.
The Applicant requested the extension of use of sodium alginate (E 401) to the category of food category 4.1.1 (entire fresh fruits and vegetables) and specifically on: citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranates at levels of quantum satis.
2.11. Dietary exposure assessment
The Applicant did not provide an exposure assessment. They stated that it was ‘not expected that sodium alginate would migrate to the internal edible part of the peel, and that due to the specific foods they have listed as part of the application (citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranates) the additive would still very unlikely be consumed directly from the peel.’
For context, the AEJEG considered the evidence presented in the EFSA 2017 Opinion on the level of exposure from food: ‘In the maximum level exposure assessment scenario, mean exposure from alginic acid and its salts (E 400–E 404) from their use as food additives ranged from 35.1 mg/kg bw per day in the elderly to 300.3 mg/kg bw per day in toddlers. The 95th percentile of exposure from alginic acid and its salts (E 400–E 404) ranged from 66.1 mg/kg bw per day in elderly to 388.6 mg/kg bw per day in children. In the refined estimated exposure scenarios, in the brand-loyal scenario, mean exposure from alginic acid and its salts (E 400–E 404) from their use as food additives ranged from 11.1 mg/kg bw per day in infants to 192.0 mg/kg bw per day in toddlers. The high 95th percentile exposure from alginic acid and its salts (E 400–E 404) ranged from 31.2 mg/kg bw per day in elderly to 276.7 mg/kg bw per day in infants.’
The AEJEG also considered the evidence presented in the EFSA 2017 Opinion on the level of exposure from other sources: ‘Alginic acid and its salts are used as active ingredients or excipients in pharmaceutical products (e.g. Martindale, 2014). As active ingredients alginic acid, magnesium alginate and sodium alginate are given, sometimes formulated in combination with carbonates and other antacids (aluminium hydroxide), in the management of gastroesophageal reflux disease (GERD). Alginic acid or its salts react with gastric acid to form a viscous gel acting as mechanical barrier to reduce reflux of gastric content (Kapadia & Mane, 2007; Mandel et al., 2000; Martindale, 2014; Reimer et al., 2016). In medicinal products, the adult single dosages for sodium alginate is 500–1000 mg, given up to four times daily and for alginic acid it is 300 mg, given up to six times daily. Alginic acids and its salts are used as excipients such as suspending and thickening agents, stabilisers for oil-in-water emulsions and as binding and disintegrating agents (Martindale, 2014).’
The AEJEG considered that both EFSA and JECFA concluded that there was no need for a numerical ADI for sodium alginate (E 401). Furthermore, the AEJEG considered the use of sodium alginate as a fruit coating as of low toxicological concern, and especially in categories of fruit where the peel would unlikely be consumed (or only consumed minimally in cases of use in food such as baking), and considering the information contained within the 2017 EFSA Opinion, on balance they did not find the lack of an exposure assessment problematic, as exposure from the proposed application would not contribute significantly to the existing exposures.
The COT noted that gastroesophageal reflux disease should be abbreviated to GORD and not GERD as used in the quoted EFSA Opinion above (EFSA ANS Panel, 2017).
2.12. Biological and Toxicological Data
2.12.1. Absorption, distribution, metabolism and excretion
The Applicant presented a study by Nakamura et al. (1988), studying the disposition of alginate salts and their effect on serum concentrations of Na, K and Ca. A single dose of alginate salt (Na, K or Ca) was administered orally to rats (at 90.4 mg/kg). No significant differences were observed in the faecal excretion or alginate content pattern in the gastrointestinal tract as a function of time as 72.7 to 79.3% of the administered alginates were excreted in the faeces in 3 days, alginates remained in the stomach for 2 hours, moving to the small intestine after 4 hours and eventually moving to the large intestine after 8 hours, remaining there after 24 hours. Finally, administration of the alginates did not affect Na, K and Ca serum levels.
The Applicant also presented a human study by Anderson et al. (1991). Five male volunteers were administered sodium alginate at 175 mg/kg bw per day for 7 days, followed by consumption of 200 mg of sodium alginate/kg bw/d for 16 days. Sodium alginate acted as a faecal bulking agent in the volunteers, leading to a significant increase (p<0.01) in daily faecal wet weight, increase in water content and daily dry weight. No changes in faecal pH were observed and no significant effects on haematological indices, plasma biochemical parameters, urinalysis parameters, blood glucose and plasma insulin concentrations, or hydrogen concentrations in breath were observed. There were no allergic responses. Although the dietary transit time remained constant for two volunteers, it decreased for two and increased slightly for one, with little resulting change in the overall mean value.
Based on this information the Applicant concluded that the study indicates that ingesting sodium alginate at a high level for 23 days did not cause effects other than those normally associated with a polysaccharide bulking agent; in particular, enzyme indicators and other sensitive indicators of adverse toxicological effects were unchanged.
2.13. Applicant’s overall conclusions on safety
The Applicant concluded that based on their own analytical data, external data and the current EU categorization of sodium alginate on peeled, cut and shredded fruit and vegetables, there will be no risk to human health with the inclusion of this additive to the proposed ‘entire fresh fruit and vegetables’ category as a surface treatment. Furthermore, due to the specific foods they have listed as a part of this application, they considered it very unlikely the additive will be directly consumed from the peel.
2.14. AEJEG Conclusions
The AEJEG has considered the application using the key information presented above.
The AEJEG acknowledged the lack of an exposure assessment related to this application, however they considered that the use of sodium alginate as a coating for fruit was of low toxicological concern, and especially in categories of fruit where the peel would unlikely be consumed (or only consumed minimally in cases of use in food such as baking), on balance they did not find the lack of an exposure assessment problematic.
Overall, the AEJEG recognised the safe history of use of E 401 within the EU and other countries. The AEJEG recognised that a number of scientific bodies, including JEFCA and EFSA have established an ADI not specified for the additive E 401, due to lack of toxicological concerns. The AEJEG concurred with this and considered the extension of use of sodium alginate for the surface coating of fruits and vegetables (specifically fresh citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranates) as described in this Application to be safe under the proposed conditions of use and to be of low toxicological concern.
3. Conclusions
To support the FSA and FSS in evaluating the dossier, the AEJEG were asked to review the dossier submitted by the Applicant and the subsequent additional information requested and advise the FSA and FSS.
The COT also reviewed the AEJEG advice and agreed with their conclusions.
The FSA and FSS agreed on the conclusions of the AEJEG in that the extension of use of the sodium alginate (E 401) as a coating material in entire fresh fruit and vegetables (citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranates) at quantum satis is safe under the proposed conditions of use.
The AEJEG advised the FSA and FSS that sufficient information had been provided to allow for an evaluation of the proposal for the modification of the conditions of use of sodium alginate to the surface of entire fresh fruit and vegetables as a coating to preserve them, there were no concerns over safety of the proposed extension of use.
The FSA and FSS therefore concluded in this assessment that the extension of use of the sodium alginate (E 401) as a coating material in entire fresh fruit and vegetables (citrus fruit, melons, pineapples, bananas, papayas, mangoes, avocados, pomegranates) as described within this application would not pose a risk to health. Therefore, there were no concerns over safety of the proposed extension of use.
Abbreviations
Acknowledgements
With thanks to the members of the AEJEG who provided advice during the course of the assessment who were: Dr Allain Bueno, Dr Claude Lambré, Dr Martin Rose, Dr Olwenn Martin, Professor Qasim Chaudhry and Dr Claire Stephenson. With additional thanks to members of COT who reviewed this assessment.