The prevalence of food allergies to mustard is growing and its uses in agriculture - as well as in the preparation of various foods and food additives - increase the risk of accidental contamination. A deepening.
1. Introduction.
1.1. Mustard, botany and uses
Mustard belongs to the family of Brassicaceae. Its most common species are:
- white / yellow mustard (Sinapis alba L.), appreciated for the aromatic properties of its seeds,
- brown / oriental mustard (Brassica juncea L.), of great interest both as a spice and for the production of edible oil,
- black mustard (Brassica nigra L.), used in the food sector to produce oil and in the pharmaceutical sector for poultices.
1.2. Prevalence of food allergies in Europe
EFSA (European Food Safety Authority) was requested by Food Safety Authority of Ireland (FSAI), in 2011, to carry out a scientific review on the prevalence of food allergies in Europe. In the hope of being able to establish any tolerance thresholds for each allergen, as well as defining the state of the art on qualitative-quantitative analytical methods. The initial research was commissioned to the University of Portsmouth (UK), which published the results in 2013. (1)
The scientific review considered the literature then available on the prevalence of food allergies in Europe and worldwide. On this basis, EFSA published in 2014 a scientific opinion on food allergies mediated and not by immunoglobulins (Ig) E, celiac disease and adverse reactions to sulphites in food. (2) A complex work, also due to the recurrence of studies based on patient statements, not confirmed by clinical diagnoses.
2. Allergy to mustard
2.1. Prevalence of allergies
EFSA could not evaluate the trends expression of mustard allergy in the population. The researchers have in fact identified one and only study on the subject, conducted in France on a sample of subjects aged 5-17. Clinical data, such as those on the prevalence of sensitization and those on the incidence of allergic reaction, are very scarce.
France - which continues to be the country with the most data available - has reported awareness of children and adults in a large range (1-28%), in the period 1983-2001. Spain follows, where however they have only been led prick test cutaneous. In Italy, the allergy to mustard, negligible according to pre-2013 studies, would be on the rise (to an undefined extent) due to the growing spread of sesame consumption and ethnic cuisine.
2.2. Risks and analysis
The risks of adverse reactions e shock anaphylactic agents appear to be greater in the adult population, although positivity was not lacking prick tests in children of 12-18 months. Hypothesizing in such cases sensitization in utero and during lactation. As well as due to possible contamination of the baby food, as already noted for peanuts and sesame.
The dose of protein which triggers allergenic reactions in subjects sensitive to mustard is estimated by EFSA to be about 1 mg. (2) Although reg. EU 1169/11 does not provide, please note, any tolerance threshold. And in any case it is difficult to apply the UNI EN 15663-1 standard to its seeds, due to the few available comparison data. (3)
2.3. Mustard and allergies, updates
The latest review available science (Sharma et al., 2019) shows a significant increase in populations and shares of populations sensitized to mustard. It refers on average to 6-7% of total cases of food allergy, with a lower incidence on children (1,1% of allergies).
In France mustard is the fourth most common food allergen, in Spain is growing, in Italy a severe allergic reaction was recorded following the consumption of a pizza (cross-contamination). Canada - the second largest mustard producer in the world - has been identified as a country at risk. And so was India, its great consumer in all forms (seeds, powder, sauce and oil).
Scientific data on mustard allergy continue to be scarce, mainly limited to the results of skin prick tests.
However, there has been an increase in the evidence of skin reactions and respiratory problems among individuals allergic to mustard, including as a result of inhaling their pollen. (4)
2.4. 'Hidden mustard' risk
A real risk not to be underestimated concerns the 'hidden mustard'. That is to say the presence of mustard in concentrations so low as to be unidentifiable, which can however trigger sudden allergic reactions, of moderate or even serious entity, depending on the individual sensitivity. Hidden mustard can therefore represent a cause of immune reactions of unidentified origin (so-called idiopathic anaphylaxis).
Contamination from mustard to levels close to the detection threshold can derive from its use in food as a thickener or as a stabilizer, or to give a 'pungent touch' (and allergenic) to raw materials and food products. And it is necessary to strengthen monitoring, first of all in self-control, to ensure correct information for allergic consumers. (4)
2.5. Hidden mustard and other Brassicaceae
A revision systematic of prevalence, role and causes of contamination by hidden allergens (Taveniers et al., 2014) has shown that they are the basis of 22,4% of food allergenic reactions. The use of seeds in herbal blends is an additional risk factor, which therefore extends to several food categories.
Another factor risk is represented by the structural similarity of some mustard allergens - the 2S reserve proteins, very similar among other things to those of other allergens (eg walnut, celery) - with those of other species of the Brassicaceae family. However, the specific additional labeling requirement is limited to mustard only. (5)
It is hoped therefore an updated review by EFSA, in view of a possible integration of the list of allergens to be analyzed in food and mandatory information on the label (EU regulation 1169/11, Annex II), for the best protection of consumers allergic to proteins in question.
3. Use of mustard in agriculture
3.1. Use of mustard as a fungicide
ITAB, Institut Technique de l'Agriculture Biologique (ITAB), has obtained the authorization of a mustard seed powder (from the three white, oriental and black species) as a fungicide to be applied to the kernels of soft, hard and spelled wheat for protection from some caries agents. EFSA and Member States shared the substantial absence, or minimal likelihood, of wheat contamination risks. (6)
The mustard seed powder and water can therefore be used, even in organic farming, to protect the seeds from fungal attacks. In compliance with the methods of use specifically defined in a specific report (SANTE / 11309/2017), to be reported in the labeling and technical data sheet of the organic plant protection product. (7)
3.2. Use of mustard in green manure
The capacity of mustard to give structure and organic substance to the soil - as well as to counteract the development of pathogens, nematodes and weeds - has favored the use of white mustard and oriental mustard for green manure (cultivation for the purpose of burying in the soil), in the USA, especially in the potato fields. Its effectiveness is largely attributed to the glucosinolates it contains, which are capable of carrying out a bio-fumigating action. (8)
In Veneto the white and brown mustard, experimented as green manure in view of various spring crops, have shown nematicide and biofumigant properties respectively. Mustard has also turned out to be the best crop among the Brassicaceae, to incorporate phosphorus, nitrogen and potassium. (9)
3.2.1. Green manure of mustard, alternations
Green manure of mustard was performed, before potatoes and wheat, also in the project Best4Soil, in Horizon 2020, where Italy participates through the Research Center for Vegetable Production (CRPV) of Cesena. With the aim of guaranteeing high productivity in the long term, also thanks to the containment of diseases and nematodes. (10)
The changes immediately following the green manure of mustard are mainly flax and potato. Other crops, cereals and vegetables, are instead recommended in rotation for the following year. (11)
3.3. Association of mustard with other plants
The consociation mustard has been tested on numerous crops - banana, flax, beans, chickpeas, coriander, oats, peas, lentils, wheat, etc. - and it has proved very useful for the fight against aphid infestations. (12)
The use of mustard in intercropping it has also proved to be very effective in guaranteeing a better production of legumes, with particular regard to chickpeas and peas (13,14).
3.4. Use as a phyto-purifier
The variety of oriental mustard it has been shown to be potentially valid for removing residues of heavy metals, antibiotics and antibiotic-resistance genes from the portion of soil bordering the rhizosphere.
These effects they are attributed to the ability of mustard to promote the development of a community of rhizobacteria able to carry out purification, especially from antibiotics. (15)
3.5. Corroborating action
In organic farming Ministerial Decree 18.7.18 n. 6793 has admitted the use as a corroborating substance of unrefined mustard oil (obtained exclusively by mechanical pressing, subsequent filtration and dilution in water, with the only possible addition of Tween 80 as an emulsifier). Identical methods of use can be followed in the so-called 'integrated agriculture' (16,17).
3.6. Mustard in integrated production regulations
Different disciplinary - in the context of the so-called SQNPI (National Quality System Integrated Production) - contemplate the use of mustard in agriculture, in various formulations. A couple of examples:
- the Abruzzo Region recommends the use of oriental mustard for green manure before strawberries and vegetables destined for the IV range, by virtue of its properties of partial soil disinfection, (18)
- Emilia-Romagna indicates the use of mustard varieties resistant to nematodes in precession or succession to sugar beet and seed. In addition to mustard oil as a restorative, (19)
- the use of mustard as a green manure crop is also indicated in private production regulations. For example, the Virgo collective brand productions are mentioned, where its use is recommended as an interlayer, before renewal crops or spring sowing of cereals. (20)
PROJECTED IMPACT
The estimate the exact prevalence of mustard allergies is still difficult, in the face of still scarce data. The main data available concern the results of skin prick tests and a few double-blind tests against placebo, essentially limited to the main consumer countries (France, Spain, Canada, India, Finland). The main species involved appear to be white mustard and oriental mustard (black mustard appears to be excluded).
An important risk it consists of the presence of 'hidden mustard' - difficult to detect and not indicated on the label - in many foods and preparations, which could also cause idiopathic anaphylaxis (ie not attributed to a specific event). The use of the different species of mustard is also spreading in agriculture, as a green manure crop (burial in the soil). And the possibility of allergenic contamination of the agricultural productions that follow it has been affirmed.
The crops mainly involved seem to be potatoes, sugar (and seed) beets, wheat and other cereals, IV range, strawberries. Since proteins are resistant to various processes and heat treatments, it is recommended that operators pay the utmost attention to avoid omitting the necessary information to allergic consumers in the event of cross-contamination.
Dario Dongo and Andrea Adelmo Della Penna
Footnotes
(1) University of Portsmouth (2013). Literature searches and reviews related to the prevalence of food allergy in Europe. EFSA supporting publication EN-506. https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/sp.efsa.2013.EN-506
(2) EFSA NDA Panel (2014). Scientific opinion on the evaluation of allergenic foods and food ingredients for labeling purposes. EFSA Journal 12 (11): 3894, https://doi.org/10.2903/j.efsa.2014.3894
(3) Ministry of Health (2014). Food allergies and consumer safety - Policy document and state of the art. DGISAN Office V, https://www.salute.gov.it/imgs/C_17_pubblicazioni_2134_allegato.pdf
(4) Sharma et al. (2019). A Comprehensive Review on Mustard-Induced Allergy and Implications for Human Health. Clinic. Rev. Allerg. Immunol. 57: 39-54, https://doi.org/10.1007/s12016-017-8651-2
(5) Taveniers et al. (2014). Species-specific PCR method for the detection of mustard species (Sinapis alba, Brassica nigra, Brassica juncea) as potential “hidden” allergens in foods. Lab info 12, https://www.favv-afsca.be/laboratories/labinfo/_documents/2014-07_labinfo12-p23_en.pdf
(6) EFSA (2017). Outcome of the consultation with Member States and EFSA on the basic substance application for mustard seeds powder from Sinapis alba (Brassica alba), Brassica juncea and Brassica nigra for use in plant protection as fungicide. EFSA Supporting Publication EN-1169, https://doi.org/10.2903/sp.efsa.2017.EN-1169
(7) EU Reg. 2017/2066, approving mustard seed powder as basic substance in accordance with Regulation (EC) No. 1107/2009. EUR-Lex, https://bit.ly/2XDTeb7
(8) Andrew McGuire (2016). Mustard green manures. Washington State University Extension Bullettin EB1952E: FS219E, https://bit.ly/39jd1in
(9) Veneto Agriculture (2008). Spring green manure crops. 2007 experimental results in the agricultural sector. VA Experimental Centers Sector, https://bit.ly/2VVgL6B
(10) Best4Soil (2020). Crop rotation: practical information. https://www.best4soil.eu/assets/factsheets/it/12.pdf
(11) Fiorella Stagno (2018). Management of cultivation techniques to implement soil fertility in organic citrus groves. Social Farming 2.0, https://bit.ly/2XuTokP
(12) Sarker et al. (2007). Effect of intercropping of mustard with onion and garlic on aphid population and yield. J. Bio.-Sci. 15: 35-40, https://doi.org/10.3329/jbs.v15i0.2200
(13) Singh et al. (2019). Performance of Chickpea-Mustard Intercropping on Yield and Economics of Chickpea and Mustard Crop under Different Fertility Management and Various Row Combinations. International Journal of Current Microbiology and Applied Sciences 8 (1): 236-249, https://doi.org/10.20546/ijcmas.2019.801.027
(14) Chapagain et al. (2018). Intercropping of maize, millet, mustard, wheat and ginger increased land productivity and potential economic returns for smallholder terrace farmers in Nepal. Field Crops Research 227: 91-101, https://doi.org/10.1016/j.fcr.2018.07.016
(15) Cui et al. (2021) Ryegrass (Lolium multiflorum L.) and Indian mustard (Brassica juncea L.) intercropping can improve the phytoremediation of antibiotics and antibiotic resistance genes but not heavy metals. Science of the Total Environment 784: 147093, https://doi.org/10.1016/j.scitotenv.2021.147093
(16) CCPB (2020). Organic production standard. Edition 2/2014 Rev. 5, https://bit.ly/3zt0Mdw
(17) SQNPI (2020). National guidelines for integrated production 2021 For the preparation of the regional specifications / agronomic technical section referred to in point 12.2.2 of the document: SQNPI - Adhesion, Management, Control / 2021. Rev. 5, https://bit.ly/3nPBB2E
(18) Abruzzo Region (2021). Integrated Production Regulations 2021 - Agronomic techniques. Agriculture Department, https://bit.ly/3AstkVM
(19) Emilia-Romagna Region (2021). Integrated production regulations - General rules. Directorate-General for Agriculture, Hunting and Fishing, https://bit.ly/3Cwo4B4
(20) Virgo Grain (2012). Disciplinary for the production, transformation and marketing of Virgo brand products. https://bit.ly/3Cqpr4s
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in Food Technologies and Biotechnologies, qualified food technologist, he follows the research and development area. With particular regard to European research projects (in Horizon 2020, PRIMA) where the FARE division of WIISE Srl, a benefit company, participates.
