Acetylated oxidised starch
Chemically modified starch used to thicken and stabilise processed foods. EFSA flagged a data gap for its use in baby foods, pending further study.
EFSA identified missing absorption and metabolism data for E1451 specifically, and raised a concern about its use in foods for infants at maximum permitted levels. The gap has not been closed.
What is it?
A starch derived from plant sources (typically maize, wheat, potato or tapioca) that has been treated with two chemical processes: oxidation and acetylation. Oxidation opens up the starch granule structure; acetylation adds acetyl groups that reduce the tendency of the starch to gel or congeal. The combined modification produces a starch that behaves differently from the unmodified original, giving manufacturers more control over texture.
What does it do?
Acts primarily as a thickener and stabiliser. The double modification means it stays smooth and pourable over a wide temperature range, resists separation on freezing and thawing, and holds its texture in acidic or long-shelf-life products. It prevents the watery separation (syneresis) that plain starch would cause in chilled or frozen sauces.
Where you will see it
Most commonly found in ready-made sauces, gravies, soups, salad dressings, and low-fat dairy products where a stable, smooth texture is needed through refrigeration or freezing. Also authorised in certain dietary foods for babies and young children for special medical purposes. On a UK label it appears as 'acetylated oxidised starch' or 'E1451'.
What the science says
Animal toxicology: kidney and bladder findings at high doses
A 90-day rat study found kidney changes and urinary bladder hyperplasia at very high doses (roughly 5,900 mg per kg of body weight per day). Long-term rat studies also showed kidney mineral deposits (pelvic nephrocalcinosis) at elevated exposures. EFSA concluded these specific kidney effects were not relevant to humans because rats are unusually sensitive to this type of injury, and typical food exposure is far below the doses tested. However, these were the effects that set the toxicological upper limit for the assessment.
A 90-day rat study established a no-observed-adverse-effect level of 5,900 mg/kg body weight per day, based on urinary bladder hyperplasia and kidney changes.
Long-term rat studies showed pelvic nephrocalcinosis (kidney mineral deposits) at high intake levels; the Panel considered this effect specific to the rat model and not predictive of human risk.
Genotoxicity assessed by modelling only, not direct testing
EFSA did not require direct genotoxicity tests for E1451, instead using computer-based structural analysis (in silico) of its chemical subunits. The Panel concluded there was no reason to suspect genotoxic potential. No in vitro or in vivo genotoxicity studies specific to E1451 were conducted or required. This approach is standard for modified starches but means direct test data do not exist for this specific form.
EFSA applied in silico analysis and concluded modified starches, including E1451, do not raise concern for genotoxicity, without requiring dedicated in vitro or in vivo tests.
Data gap: how the body handles E1451 is not fully characterised
EFSA noted that absorption, distribution, metabolism and excretion (ADME) data were absent specifically for E1451 and one other modified starch (E1452). The Panel bridged this gap by reading across from better-studied related starches in the same group, concluding the overall database was sufficient for adults. The Panel did not close the gap with new data, and it remains a documented limitation in the formal assessment.
The EFSA Panel noted the absence of ADME data for E1451 (and E1452) specifically, and applied a read-across approach from structurally similar modified starches to compensate.
Infant use: EFSA recommended further data generation
E1451 is authorised at up to 50,000 mg/kg in a narrow category of dietary foods for babies and young children for special medical purposes. During the 2017 re-evaluation, EFSA recommended that additional safety data be generated for this use specifically, citing the vulnerability of infants and the relatively high permitted maximum level in this category. This recommendation to generate further data is a formal concern on record, distinct from the position for adults.
EFSA recommended data generation to address safety for infants, noting the maximum permitted level of 50,000 mg/kg in dietary foods for babies (category 13.1.5.2) and the particular vulnerability of that population.
Where it stands with the regulators
Who should be careful
No population group is formally required to avoid E1451. Parents of infants fed specialist medical foods that use E1451 may wish to note that EFSA recommended further data generation for this specific use. People with wheat or maize allergies should check the starch source, as the modification process does not eliminate source proteins entirely. Look for 'acetylated oxidised starch' or 'E1451' in the ingredients list.
The honest read
E1451 is a well-established modified starch that has been used in food manufacturing for decades. For adults eating it in ordinary processed foods, the toxicological picture from animal studies is reassuring at realistic intake levels. The honest qualification is that EFSA's 2017 formal review flagged two things: a missing piece in the data (how the body handles this specific modified starch, filled in by analogy rather than direct study), and a specific recommendation that more data be collected before its use in infant specialist foods can be considered fully characterised. Those gaps are on the record. The science for adult general-population use is more complete than for infant use.
Related additives
Common questions
Is E1451 banned in the UK?
No. E1451 is on the UK FSA approved-additives list and remains permitted under assimilated EU Regulation 1333/2008. It was re-evaluated by EFSA in 2017 and continued authorisation was confirmed, with a recommendation for further data on infant use.
Why did EFSA flag a concern about infant foods containing E1451?
EFSA's 2017 re-evaluation noted that the permitted maximum level in specialist infant foods is high (50,000 mg/kg), and that infants are a more vulnerable population. The Panel recommended generating additional safety data for this specific use. It did not withdraw authorisation, but the recommendation is a formal gap on record.
What foods contain E1451?
Mainly processed sauces, gravies, soups, salad dressings, chilled and frozen ready meals, and low-fat dairy or dessert products that need a stable texture through refrigeration or freezing. It also appears in certain specialist dietary foods for infants with medical conditions. Check the ingredients list for 'acetylated oxidised starch' or 'E1451'.
Is E1451 vegan?
Yes, in the vast majority of cases. The starch source is a plant (typically maize, wheat, potato or tapioca) and the chemical modification uses acetic anhydride and an oxidising agent, not animal-derived inputs. The starch source itself is worth checking if you have a wheat allergy, as wheat-derived E1451 would carry wheat proteins.
Sources
- EFSA Panel on Food Additives and Nutrient Sources (ANS) - Re-evaluation of oxidised starch (E 1404) and related modified starches including acetylated oxidised starch (E 1451) as food additives - EFSA Journal 2017
- PMC full text of EFSA re-evaluation of modified starches including E 1451
- UK FSA Approved Additives and E Numbers list
- UK FSA regulated products register: E 1451 Acetylated oxidised starch
- Assimilated Regulation (EC) No 1333/2008 on food additives - Annex II (legislation.gov.uk)
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