Tomato paste is among the products most susceptible to food fraud, with practices that endanger health, cheat consumers and damage the market. Two recent studies, conducted in Lebanon (Habib et al., 2025) and Ghana (Boakye et al., 2024), reveal widespread adulteration, violating international standards (Codex Alimentarius) and national laws.
Thickeners, dyes and other fraud in tomato concentrate
The most common food fraud in tomato concentrate is the addition of low-value thickeners such as starches and by-products of other processes.
The addition of undeclared starch poses several critical issues:
– it may pose a health risk to people with allergies to cereals containing gluten or intolerances to the latter (e.g. celiac disease), if derived from them;
– dilutes the natural tomato content, thus reducing the concentration of nutrients, micronutrients (e.g. vitamins) and valuable phytocomplexes (e.g. lycopene);
– can alter the texture and palate feel of tomato paste, making it thicker and potentially masking quality deficiencies such as low tomato solids content.
Food fraud investigated in Ghana has also revealed the addition of toxic synthetic dyes.
The Lebanese study: starch fraud and ineffective controls
The Lebanese study (Habib et al., 2025) examined 41 samples of tomato paste, taken from markets in Beirut, the Bekaa Valley and Tripoli in the Levant.
With regard to origin, 31 products were local and 10 imported from Syria, Iran, Egypt, Saudi Arabia, the United Arab Emirates, Bulgaria and China.
The evaluation focused on starch detection and product quality, concentrating on parameters such as total soluble solids, Bostwick consistency, viscosity, titratable acidity, colour and dry matter content, while also assessing label information (origin, price, expiry date).
The anti-fraud tests
The samples were subjected to three different analyses:
1. iodine test. The chemical element (at a concentration of 0.1%) reacts with starch to form a dark blue colour (rapid qualitative method). The presence of starch was therefore indicated by the development of this colouration in the tomato concentrate;
2. measurement of the total soluble solids (TSS) in °Brix to verify the actual raw material concentration. The test mainly indicates the sugar content in fruit and tomato products;
3. physico-chemical analysis to measure pH, titratable acidity (with NaOH titration) and colour (CIELAB colorimeter).
Results of the Lebanese study
The results of tests conducted in Lebanon revealed numerous violations of Libnor Standard NL 767:2012 and Codex Alimentarius (Codex Stan 57-1981), which explicitly prohibit the use of starch in tomato paste and require at least 24% total soluble solids (TSS):
- 41% of the samples had TSS (soluble solids) values different from those declared on the label (trade fraud)
- 37% contained undeclared starch (worse in local products: 48% non-compliant)
- 27% had TSS <24%, a sign of dilution with water.
The Ghanaian study
Boakye and colleagues (2024) had conducted a similar study in Ghana, where tomato paste is a highly valued product due to its versatility of use, nutritional value and practicality, including storage, and is therefore very popular with all classes of consumers.
Sampling was carried out in the country’s two largest cities, Accra and Kumasi, in the respective markets of Makola, Asafo and Central.
Of the 40 samples (from 8 brands), in 5 cases (62.5%) were imported. This confirms the official data, according to which most of the 100,000 tonnes of tomato paste consumed annually in Ghana comes from abroad.
Aim of the Ghanaian study
The researchers performed the usual tests to assess the quality of the sampled tomato paste, the presence of starch and the artificial colouring agent erythrosine, which are considered adulterants according to the product specifications given by the Ghana Standards Authority (GSA) and the Ghanaian FDA.
We have already reported on the intrinsic quality (≥24% total soluble solids) and the addition of starch (not declared on the label) in the Lebanese study, with regard to the risks for coeliac consumers and the vulnus to the nutritional and organoleptic profile of the tomato paste.
Hunt for the toxic dye
A novel aspect of the Ghanaian study, in comparison to the Lebanese one, concerns the search for the presence of the artificial dye erythrosine fraudulently added to tomato paste.
This red food colouring has been reported to induce endotoxic and mutagenic effects in HepG2 cells, impair thyroid function and inhibit enzymes that metabolise drugs. It has caused hyperthyroidism and thyroid cancer in rodents. It is linked to cognitive alterations and behavioural disorders in children.
Due to this scientific evidence, erythrosine is banned in Ghana, as well as in Norway and Spain. In the European Union, where it is identified as E127, it is still only authorised under Regulation (EC) 1333/2008 for colouring cocktail cherries and candied cherries.
In the USA, on 15 January 2025, the FDA (Food and Drug Administration) revoked (by a wide margin) the authorisations for the use of erythrosine (FD&C Red No. 3, also known as Red Dye No. 3). Manufacturers using FD&C Red No. 3 in food and drugs will have until 15 January 2027 or 18 January 2028, respectively, to reformulate their products.
Tests on Ghanaian samples
To analyse how well the samples collected in Ghana matched the national standards, the researchers used
1. light microscopy: the starch granules become visible with a blue-black colouration following the sprinkling of iodine;
2. HPLC (liquid chromatography): a technique that detects erythrosine with an accuracy of 99%;
3. enzymatic tests, which quantify starch by hydrolysis with α-amylase.
Results of the tests in Ghana
The result of the tests carried out by the researchers confirmed the pervasiveness of fraud in tomato concentrate. It was indeed found that
- 100% of the Ghanaian samples contained starch, with 3 products qualified by a concentration of more than 10% (more than 10 g/100 g), against the 1.55 g of the authentic product, i.e. a concentrate made simply by withdrawing the tomato water by cooking;
- 25% (2 out of 8) contained the colouring agent erythrosine, which is banned and (obviously) not indicated on the label;
- 50% did not reach 24% total solids.
The EU scenario
Tomato paste fraud in the European Union, according to the notices registered in the Rapid Alert System for Food and Feed (RASFF), does not seem to resemble the scenario described in Lebanon and Ghana.
Between March 2022 and December 2024, the RASFF reports only 16 alerts, concerning the use of preservatives (not authorised in tomato paste) in products imported from Syria, Lebanon, Turkey and Egypt, and the presence of mycotoxins in Italian products.
Conclusions
In Lebanon and Ghana, tomato paste is a very popular foodstuff, widely used in domestic preparations: an ideal target for criminals who get unjustly rich on food. Many new cheap brands emerge in local markets and speculate with adulterations that the consumer is unable to assess.
Market and consumer protection can only be increased by strengthening supervision:
- spot checks in the markets (rapid tests with iodine and refractometers);
- harsher penalties for those who violate standards (e.g. immediate withdrawal);
- clear labels mentioning all ingredients: today 41% in Lebanon and 25% in Ghana of tomato paste labels lie. An unacceptable reality.
Marta Strinati
Cover art copyright © 2025 Dario Dongo (AI-assisted creation)
References
– Boakye A, Avor DD, Amponsah IK, Appaw WO, Owusu-Ansah L, Adjei S, Baah MK, Addotey JN. Quality Assessment of Tomato Paste Products on the Ghanaian Market: An Insight Into Their Possible Adulteration. Int J Food Sci. 2024 Sep 9;2024:8285434. doi: 10.1155/2024/8285434. PMID: 39285917; PMCID: PMC11405106.
– Habib F, Khazaal S, Bou Yazbeck E, Debs E, Sunoqrot S, Louka N, El Darra N. Adulteration and quality assessment of tomato paste: a study of the Lebanese market. Front Nutr. 2025 Apr 28;12:1559287. doi: 10.3389/fnut.2025.1559287. PMID: 40357045; PMCID: PMC12066644.
– RASFF. Notifications concerning tomato paste. Consulted on 18 June 2025
– Regulation (EC) No 1333/2008 of the European Parliament and of the Council of 16 December 2008 on food additives (Text with EEA relevance). Eurlex https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333
– U.S, Food & Drug Administration. FD&C Red No. 3. https://www.fda.gov/industry/color-additives/fdc-red-no-3
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
