Following a recent case of botulinum toxin infection, the Ministry of Health in Italy has adopted a circular recommending that operators include the wording ‘boil the product for at least 5 minutes’ on the label of fresh soups and similar products, so-called REPFEDs. (1)
The question remains whether the proposed solution is really suitable to guarantee the health of consumers with respect to a serious risk of food safety on products placed on the market. Is a warning on the label enough?
1) Fresh soups and similar products, REPFEDs
Fresh soups and similar products (e.g. cream soups, vegetable purees sold in refrigerated counters) – also known as REPFEDs (Refrigerated Processed Food with Extended Durability) – have been successfully developed by the industry to respond to the changing eating habits of consumers.
Customers, in fact have ‘less and less time to cook’, the ministry indicates, and purchase products that integrate the relative service quota, from salads to ready meals. Favoring those that are as similar as possible to fresh ones, free from synthetic preservatives and subjected to mild heat treatments. Such as REPFEDs.
2) REPFEDs and botulism
The experience developed at the National Reference Centre for Botulism (CNRB) – due to the occurrence of numerous episodes of food poisoning – demonstrates that REPFEDs can support the development and toxinogenesis of clostridia producing seriously dangerous toxins.
Maintaining the cold chain in the logistic, commercial and domestic phases is therefore strictly related to the food safety of fresh soups and similar products of use. But exceeding the maximum storage temperature (+6 °C), in real life, is recurrent.
3) Opinion of the Higher Institute of Health
The Higher Institute of Health (ISS), at the request of the Ministry of Health, has adopted a scientific opinion on the best available manufacturing practices to ensure the food safety of fresh soups and similar products (REPFEDs). Evaluating in particular:
-heat treatments necessary to inactivate spores capable of generating botulinum toxins;
-the hypothesis of adding to such products food additives with substances with antibotulinum action;
– the methods of use suitable for inhibiting botulism on this category of products, to be reported on the label.
3.1) Clostridia and heat treatments
The opinion of ISS first of all highlighted that:
-almost all cases and outbreaks of foodborne botulism are related to the development and toxigenesis of strains of clostridia producing BoNTs (Botulinum neurotoxins) with proteolytic metabolism;
-all strains isolated from clinical samples and food residues of cases and outbreaks related to REPFED consumption belong to group I (C. botulinum with proteolytic metabolism).
The pasteurization heat treatments (+90°C for at least 10 minutes or equivalent treatments) can inactivate the toxins but not the spores of BoNT-producing clostridia.
The spores, as seen, can be destroyed by exposure to +121 °C for 3 minutes (2,3). Other technologies not combined with heat treatments are, on the contrary, effective (4,5).
3.2) Cold chain, microbiological risk
Microbiological safety of fresh soups and similar products (REPFEDs) ‘with respect to the danger of BoNT-producing clostridia, safety is ensured only if the cold chain is scrupulously respected (storage at a temperature ≤ +6 °C) for the entire shelf life of the product’.
Average temperatures of domestic refrigerators are, according to ISS, between 8,5°C and 9,5°C. The risk of developing BoNTs in fresh soups, cream soups and similar products stored at these temperatures is therefore serious in terms of probability of occurrence and harmfulness of the danger.
3.3) Ready-to-heat soups and food labels
Fresh soups and more generally ‘REPFEDs based on plant products (e.g. cream soups, soups, soups with cereals) must be considered ready to heat (products to be cooked)’.
The label of these products should therefore also report the indication ‘boil the product for at least 5 minutes’, taking into account that:
-the literature does not offer certainties on the minimum denaturation times of BoNTs in the various REPFED references;
-this indication is easily implementable both in the kitchen and in workplaces where heating plates or microwave ovens are available;
-boiling is easily verifiable and does not require the use of a thermometer to verify that the temperature required to thermally deactivate the BoNTs has been reached.
3.4) Preservative additives
The use of additives with a preservative action – such as sodium sorbate, among others – it also requires, as is obvious:
-‘profound changes in the formulation of the references currently on the market’ and
–‘a validation of the process as well as the determination of shelf life by challenge tests’. (6)
4) Ministry of Health, what ‘solution’?
The Ministry of Health – ‘in light of the above and pending further investigation by ISS’ – indicates that ‘the quickest and most prudent solution appears to be to indicate on the product label, and in clearly visible characters, the words ‘boil the product for at least 5 minutes’.
Doubt is expressed, however, that the placing on the market of food products containing C. botulinum spores that produce neurotoxic toxins – the consumption of which can cause serious, very serious damage to the health of consumers, with even fatal outcomes – can be tolerated with a simple warning on the label. (7)
The ‘solution’ proposed by the Italian Ministry of Health must in any case be translated into an act having the force of law (since a ministerial circular, with limited circulation, does not have it at all), to be notified to Brussels pursuant to the Food Information Regulation (EU) No 1169/11, article 45.
Dario Dongo
Footnotes
(1) Ministry of Health. Former Directorate General for Food Safety and Nutrition, Office 8. Circular 30.10.24 n. 42831. Subject: REPFEDs (REfrigerated Processed Food with Extended Durability)
(2) Silvia Bonardi, Dario Dongo. Botox, a dangerous bacterium to keep away. GIFT (Great Italian Food Trade).
(3) Silvia Bonardi, Dario Dongo. Botulism in Italy, beware of homemade preserves. GIFT (Great Italian Food Trade). 29.4.20
(4) Pirazzini M, Rossetto O, Eleopra R, Montecucco C. Botulinum Neurotoxins: Biology, Pharmacology, and Toxicology. Pharmacol Rev. 2017 Apr; 69(2):200-235. doi: 10.1124/pr.116.012658
(5) Munir MT, Mtimet N, Guillier L, Meurens F, Fravalo P, Federighi M, Kooh P. Physical Treatments to Control Clostridium botulinum Hazards in Food. Foods 2023, 12(8), 1580; https://doi.org/10.3390/foods12081580
(6) Dario Dongo. Shelf-life, food security, and weight loss. An integrated approach. FT (Food Times). August 17, 2020
(7) Manuela Callari. Botulism outbreaks in Europe raise concerns for food safety. Univadis. 14.11.24 https://tinyurl.com/7napzcw5
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
