Sucrose acetate isobutyrate
A synthetic ester of sucrose used mainly in fizzy and flavoured drinks to stop clouding agents separating out and floating to the surface.
EFSA concluded SAIB does not raise concern for genotoxicity and that use at permitted levels does not raise concern.
What is it?
Sucrose acetate isobutyrate (SAIB) is a man-made ester formed by reacting sucrose (table sugar) with acetic anhydride and isobutyric anhydride. It is a thick, viscous, pale-yellow liquid. Its high density makes it useful as a weighting agent to keep oily flavour compounds suspended evenly in water-based drinks.
What does it do?
SAIB acts as an emulsifier and density-balancing agent. Citrus oils and flavour extracts are less dense than water and would normally float to the surface. SAIB is mixed into the flavour oil to increase its density until it matches the surrounding water, so the flavour stays evenly dispersed throughout the drink and the liquid stays clear rather than going cloudy or separating.
Where you will see it
Used almost exclusively in carbonated soft drinks, flavoured waters, sports drinks, and fruit-flavoured beverages where citrus or other natural flavour oils need to be held in suspension. On a UK label it will appear in the ingredients list as 'sucrose acetate isobutyrate', 'SAIB', or 'E444'.
What the science says
EFSA re-evaluation and ADI
In 2016, the EFSA Panel on Food Additives and Nutrient Sources (ANS) completed a full re-evaluation of E444. The panel reviewed animal feeding studies and metabolic data and concluded that the ADI set by the EU's Scientific Committee on Food (SCF) of 10 mg/kg body weight per day could be raised to 20 mg/kg body weight per day, bringing it into line with the earlier JECFA (1997) figure. No evidence of carcinogenicity, genotoxicity or reproductive toxicity was identified in the studies reviewed.
EFSA's ANS panel re-evaluated E444 and set an ADI of 20 mg/kg body weight per day, concluding that no genotoxic, carcinogenic or reproductive toxicity signal was present in the available data.
JECFA had previously established an ADI of 20 mg/kg body weight per day for SAIB based on a series of rat and dog feeding studies, with no adverse effects attributable to the compound at the doses used.
Metabolism and breakdown
Once ingested, SAIB is hydrolysed in the gut into sucrose, acetic acid and isobutyric acid, all of which are normal components of food and are metabolised by routine biochemical pathways. The body does not accumulate it. This metabolic profile is one reason no special exposure restriction was considered necessary beyond the ADI.
Animal and in vitro studies show SAIB is hydrolysed to sucrose, acetate and isobutyrate, all normal metabolites, with no unusual metabolic products detected.
Where it stands with the regulators
Who should be careful
No specific group is required to avoid E444. It breaks down into ordinary food components during digestion. People limiting sugar intake should note it is a sucrose-derived compound, though quantities used in beverages are small. Look for 'E444' or 'sucrose acetate isobutyrate' on the label.
The honest read
E444 is an industrially synthesised ester, but its metabolic fate is entirely routine: it breaks apart into sugar and two common organic acids. Two independent expert committees (JECFA and EFSA) have reviewed the animal feeding data and arrived at the same conclusion. The additive has been on permitted lists in the UK, EU and US for decades without a meaningful regulatory challenge. There is no active scientific debate about it at current food-use levels.
Related additives
Common questions
Is E444 banned in the UK?
No. E444 is on the UK FSA's approved additives list and is permitted under assimilated EU Regulation 1333/2008. It has been authorised without interruption in both the UK and EU.
Why is E444 used in soft drinks instead of something simpler?
Citrus and other flavour oils are less dense than water and float to the top without help. SAIB is blended into the flavour oil to match its density to the surrounding water, keeping the drink evenly flavoured and visually clear. Very few alternative weighting agents are approved for food use.
What foods contain E444?
Mainly carbonated soft drinks and flavoured waters that use citrus or tropical flavour oils, particularly those marketed as 'cloudy' or naturally flavoured. It is rarely found outside the beverage category.
Is E444 vegan?
Yes. Sucrose acetate isobutyrate is derived entirely from plant-based sucrose and two synthetic acid anhydrides. No animal-derived ingredients are involved in its production.
Sources
- Re-evaluation of sucrose acetate isobutyrate (E 444) as a food additive - EFSA Journal 2016
- UK FSA Approved Additives and E Numbers
- EFSA panel concludes E 444 limit can be doubled - Food Navigator 2016
- JECFA monograph on sucrose acetate isobutyrate
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