Beta-apo-8'-carotenal
A synthetically produced orange-red pigment from the carotenoid family, used to colour fat-based foods such as processed cheese, margarine, and soft drinks.
What is it?
Beta-apo-8'-carotenal (also called apocarotenal or CI Food Orange 6) is a C30 carotenoid compound. It occurs naturally in small quantities in spinach, citrus fruits, and tangerines, but the form used in food manufacturing is produced by chemical synthesis from carotenoid precursors. It appears as a dark red crystalline powder, dissolves in fats and oils but not in water, and produces an orange to orange-red colour in food.
What does it do?
It works as an oil-soluble colouring agent: dispersed in the fat phase of a food product, it imparts a stable yellow-to-reddish-orange hue. It also has weak pro-vitamin A activity, roughly half that of beta-carotene, because it can be partially converted to retinoids in the body, though this conversion is limited and does not meaningfully contribute to vitamin A intake at normal food-additive levels.
Where you will see it
Mainly found in fat-based products where an orange colour is wanted: processed and flavoured cheeses, margarine, salad dressings and sauces, confectionery and gummy sweets, fruit juices and soft drinks, jams and jellies, and baked goods. A 2003 retail survey found its actual use in UK products was limited. On an ingredient label it appears as 'beta-apo-8'-carotenal', 'apocarotenal', or 'E160e'.
What the science says
Genotoxicity: lab signal examined and not confirmed in animals
Laboratory studies using isolated rat liver cells found that apo-8'-carotenal caused chromosomal damage at concentrations from 0.1 to 10 micromolar. However, EFSA noted that primary rat hepatocytes have an unusually high spontaneous rate of chromosomal abnormalities, the increases were small and not dose-related across a 10,000-fold concentration range, and an in vivo rat bone marrow micronucleus test was negative. On that basis EFSA concluded the in vitro findings did not indicate a real genotoxicity concern.
Apo-8'-carotenal induced statistically significant increases in micronuclei and chromosomal aberrations in primary rat hepatocytes at 0.1-10 micromolar concentrations.
In vivo rat bone marrow micronucleus test was negative; EFSA concluded in vitro and in vivo genotoxicity studies together do not give reason for concern.
ADI history: kidney finding led to two rounds of regulatory review
A 13-week rat feeding study initially showed eosinophilic droplets (a marker of protein accumulation) in kidney cells at 10 mg/kg body weight per day. EFSA set an ADI in 2012 based on that finding as the lowest observed adverse effect level. Two years later, after re-examining the original kidney slides under better visualisation, the Panel reclassified the effect level and raised the no-observed-adverse-effect level to 30 mg/kg body weight per day, resulting in a threefold higher ADI.
EFSA 2012 set an ADI of 0.05 mg/kg body weight per day using a LOAEL of 10 mg/kg bw/day from a 13-week rat study and an uncertainty factor of 200.
After re-examination of kidney slides, the NOAEL was revised to 30 mg/kg bw/day; EFSA raised the ADI to 0.3 mg/kg bw/day and concluded current food-use levels are not of safety concern.
Beta-carotene breakdown products and lung cancer in smokers
Two large clinical trials (ATBC and CARET) found that high-dose beta-carotene supplements increased lung cancer incidence in heavy smokers by roughly 18-28%. Laboratory researchers proposed that oxidative breakdown products of beta-carotene, including apo-8'-carotenal, may be responsible by causing chromosomal damage in lung cells. This research concerns pharmacological supplement doses, not the trace amounts contributed by food colouring.
The CARET trial (18,314 participants) was stopped early after high-dose beta-carotene supplements increased lung cancer incidence (relative risk 1.28) in smokers and asbestos-exposed workers.
Alija et al. identified cytotoxic and genotoxic beta-carotene breakdown products in primary rat hepatocytes, with apo-8'-carotenal among the compounds studied as a potentially relevant oxidative breakdown product in the context of the ATBC and CARET supplement trial findings.
Where it stands with the regulators
Who should be careful
No specific group needs to avoid it at normal food-additive levels. People who already take high-dose vitamin A or retinoid supplements, and pregnant women taking retinol supplements, may wish to note that E160e contributes a small additional vitamin A precursor load, though the contribution from food colouring is negligible in practice. Look for 'E160e', 'beta-apo-8'-carotenal', or 'apocarotenal' on the label.
The honest read
E160e is one of the more straightforward food colours in the carotenoid family. It has been in commercial food use since the 1960s, has been through two full EFSA re-evaluations, and its ADI was revised upward (not downward) once regulators got better data. The genotoxicity question was raised in laboratory studies but not confirmed in live animals, and EFSA did not treat it as an unresolved concern. The main scientific interest in this chemical family centres on high-dose carotenoid supplements and lung cancer in smokers, which is a mechanistically different scenario from the microgram-level exposure from food colouring. Its actual use in UK food products is limited.
Related additives
Common questions
Is E160e banned in the UK?
No. E160e is an authorised food colour in England, Scotland, and Wales under the UK FSA approved-additives list and assimilated EU Regulation 1333/2008. It belongs to Group III food colours, which are subject to a combined maximum level in permitted food categories.
Did EFSA raise any concerns about E160e?
EFSA reviewed it twice, in 2012 and 2014. The 2012 review noted a kidney finding in rats that prompted a cautious ADI. After re-examining the original tissue slides in 2014, the panel concluded the kidney effect was less significant than initially assessed, and raised the ADI threefold to 0.3 mg/kg body weight per day. Genotoxicity was investigated after laboratory signals in isolated liver cells; a whole-animal test was negative and EFSA did not carry a genotoxicity concern forward.
What foods contain E160e?
In the EU and UK it is permitted in flavoured processed cheeses, jams, jellies, margarine, salad dressings, soft drinks, fruit juices, confectionery, and soups. A 2003 UK retail survey found its actual usage in British food products was limited compared with beta-carotene (E160a).
Is E160e vegan?
Yes. The commercial form is produced by chemical synthesis from carotenoid precursors; it is not derived from animals, and is suitable for vegans and vegetarians.
Sources
- EFSA ANS Panel: Scientific Opinion on re-evaluation of beta-apo-8'-carotenal (E 160e) as a food additive, EFSA Journal 2012;10(3):2499
- EFSA ANS Panel: Scientific Opinion on reconsideration of the ADI and refined exposure assessment of beta-apo-8'-carotenal (E 160e), EFSA Journal 2014;12(1):3492
- Alija AJ, Bresgen N, Sommerburg O, Siems W, Eckl PM: Cytotoxic and genotoxic effects of beta-carotene breakdown products on primary rat hepatocytes, Carcinogenesis 2004;25(5):827-831 (PMID 14688018)
- Omenn et al.: Effects of a combination of beta-carotene and vitamin A on lung cancer and cardiovascular disease (CARET), New England Journal of Medicine 1996;334:1150-1155
- UK FSA Approved additives and E numbers
- UK FSA Regulated Products database: E 160e authorisation
- Kramer & al.: Method development and analysis of retail foods and beverages for carotenoid food colouring materials E160a(ii) and E160e, Food Chemistry 2003;80(2):193-200
- Bhosale & Bernstein: Carotenoids, beta-Apocarotenoids, and Retinoids: The Long and the Short of It, Nutrients 2022;14(7):1411
- International Association of Color Manufacturers: beta-apo-8'-Carotenal profile
- EU Commission Regulation 1129/2011 amending Annex II to Regulation 1333/2008 (UK assimilated)
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