E-numbers / Thickeners & emulsifiers / E423
also: OSA-modified gum arabic · OSA gum acacia · INS 423
Natural gum arabic chemically modified with octenyl succinic anhydride to act as an emulsifier, keeping oil and water mixed in foods and drinks.
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Gum arabic (acacia gum) is a natural plant gum harvested from Acacia senegal and related trees.
Gum arabic (acacia gum) is a natural plant gum harvested from Acacia senegal and related trees. In E423, the gum is reacted with octenyl succinic anhydride (OSA), grafting hydrophobic groups onto the polysaccharide backbone. This gives the molecule both water-attracting and oil-attracting ends, making it an effective emulsifier. The OSA-modified version differs from plain gum arabic (E414) in that it has stronger emulsifying properties while retaining the gum's natural origin.
The modified gum molecules position themselves at the boundary between oil droplets and water, reducing surface tension and stabilising the emulsion. This prevents oil droplets from clumping or rising to the surface. It also provides mild thickening and film-forming properties. In flavour emulsions, it encapsulates volatile aromatic compounds, protecting them during processing and extending shelf life.
Mainly used in concentrated flavouring emulsions that are added to soft drinks, energy drinks, and fruit-flavoured beverages. Also used in processed sauces, dressings, confectionery, and some powdered food products where it encapsulates flavour oils. On a label it may appear as 'emulsifier (E423)', 'modified gum arabic', or 'octenyl succinic acid modified gum arabic'.
EFSA's food additives panel reviewed E423 in 2010 and concluded that use as an emulsifier at the proposed levels raised no safety concern. The panel noted that no numerical acceptable daily intake could be set because the toxicological dataset was limited, but it drew on data from plain gum arabic (E414) and OSA-modified food starch (E1450) to fill the gap. A 90-day rat feeding study found no adverse effects even at the highest doses tested, and there was no evidence of mutagenicity.
EFSA concluded that OSA modified gum arabic as an emulsifier in foods at the proposed uses and use levels is not of safety concern. No numerical ADI was set; the panel read across from data on gum acacia (E414) and food starch sodium octenyl succinate (E1450).
In a 90-day rat study, no observed adverse effect levels of approximately 3,400 mg/kg body weight per day (males) and 4,050 mg/kg body weight per day (females) were derived at the highest dose tested, with no mutagenicity signals observed.
The Joint FAO/WHO Expert Committee on Food Additives (JECFA) also evaluated OSA modified gum arabic and found no toxicological concern at levels used in food. JECFA's database lists it with an acceptable daily intake classified as 'not specified', meaning the available evidence did not indicate a need for a numerical limit at typical food use levels.
JECFA listed OSA modified gum arabic with an ADI 'not specified', indicating no toxicological concern at levels used in food.
Plain gum arabic (E414) was re-evaluated by EFSA in 2017 and also raised no safety concern; that broader data set informed confidence in the modified form. The OSA modification is relatively minor in terms of the overall molecule structure, and the gum backbone is the same natural polysaccharide.
EFSA re-evaluated plain acacia gum (E414) in 2017 and found no safety concern, which informed the read-across supporting E423's regulatory assessment.
People with known acacia gum (gum arabic) allergy should be aware that E423 is derived from the same plant source as E414. Although gum arabic allergy is uncommon, it is established and can cause respiratory and skin reactions in sensitised individuals. Look for 'gum arabic', 'acacia gum', 'modified gum arabic', or 'E423' on labels.
E423 is a specialised emulsifier with a narrow set of permitted uses, mainly in flavour emulsions for drinks. The science behind it is straightforward: it is a chemically modified version of a long-established plant gum with a well-characterised safety profile. EFSA and JECFA both reviewed it and found no concern at the levels used in food. No numerical acceptable daily intake was set not because of worry but because the amounts people realistically consume are tiny and the parent gum has a long history of use. There is no credible evidence of harm in the published literature at food-relevant doses.
No. E423 is permitted in the UK and was authorised by Commission Regulation (EU) No 817/2013, which was retained in UK law after Brexit. It is included in the UK FSA's approved additives list.
EFSA concluded there was no safety concern at the levels used in food but said the toxicological dataset was too limited to calculate a precise numerical ADI. They read across from the extensive data available on plain gum arabic (E414) and a related starch emulsifier (E1450). JECFA similarly classifies the ADI as 'not specified', meaning no upper limit is considered necessary at typical intake levels.
E423 is most commonly found in flavour emulsions used to make fizzy drinks, energy drinks, and fruit-flavoured beverages. It may also appear in some sauces, dressings, confectionery, and powdered food products. It is not a widely used additive and appears in a relatively small range of products.
Yes. E423 is derived from acacia (gum arabic), a plant gum, with no animal-derived ingredients involved. It is suitable for vegans and vegetarians.
Last reviewed: 20 June 2026
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