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f221 Coffee

Whole Allergen
Code f221
LOINC 6083-0
Family Rubiaceae
Genus Coffea
Species Coffea arabica Coffea canephora Coffea liberica
Route of Exposure Ingestion
Source Material Coffee
Latin Name Coffea arabica, Coffea canephora
Common Name Coffee
Categories Food Of Plant Origin, Miscellaneous

Summary

Coffee comes from roasted seeds of trees of the Rubiaceae family. It is consumed by hundreds of millions of people worldwide due to its pleasant taste, aroma, stimulant effect and health benefits. Allergy to coffee consumption is rare, and the few clinical cases reported are likely due to other ingredients contained in the beverage, rather than to the coffee bean itself. However, in processing the 9 million tons of coffee produced each year, many coffee workers are exposed to irritating and sensitizing dust. This represents a common occupational allergy and some cases are attributable to coffee bean dust in particular. 

Allergen

Nature

Coffee is one of the most widely consumed beverages throughout the world due to its pleasant taste, aroma, stimulant effect and health benefits (1). The coffee beverage comes from roasted seeds of trees belonging to the  Rubiaceae family and the genus Coffea. Coffee plants were discovered in Africa and eventually disseminated to countries around the world, with most of the production now coming from Brazil (2, 3). Currently, there are over 100 species within the genus Coffea although only two species are actually of importance in the world market: C. arabica and C. canephora (2). The coffee bean is the seed of the coffee plant and the world’s primary source of caffeine (1). 

Taxonomy    

 

Taxonomic tree of Coffee (4)

Domain

Eukaryote

Kingdom

Plantae

Phylum

Tracheophyta

Subphylum

Spermatophytina

Class

Magnoliopsida

Family

Rubiaceae

Genus

Coffee.

Epidemiology

Worldwide distribution 

Allergic reactions to the ingestion of coffee are appear to be  rare and the results of the association between coffee consumption and asthma is inconsistent (5, 6).

Coffee is consumed by hundreds of millions people worldwide with about 9 million tons being processed every year. The processing includes removing pulps and drying the resulting green coffee beans by sunlight. Usually the beans are then roasted and/or decaffeinated and shipped worldwide. About 25 million coffee workers are exposed during the coffee processing to irritating and sensitizing dust with several additional allergens (including burlap and cockroach). Dust from coffee bean processing has been reported to elicit skin, ocular, and respiratory allergic reactions in up to 50% of coffee processing industry workers (7).

Detection

Allergic reactions to the ingestion of coffee are  rare and several studies indicate a beneficial effect in some asthmatic patients (5, 6). Case reports of allergic symptoms after coffee consumption have been attributed to other constituents, such as the preservative sodium metabisulphite (8), and to cow’s milk and/or sodium caseinate (9).

Allergic symptoms to caffeine have been reported in a small number of patients after consumption of coffee (10). Despite a lack of clinical reports investigating coffee allergy, one study including 150 people  from Iraq showed that 25.7 % had positive coffee skin prick tests (11).

Molecular Aspects

Allergenic molecules

Table adapted from Allergome.org (12).

Allergen

Source

Cof a [Leaf]

Coffea arabica, Coffee, Plants, Rubiaceae

Cof a [Seed]

Coffea arabica, Coffee, Plants, Rubiaceae

Cof a 1

Coffea arabica, Coffee, Plants, Rubiaceae

Cof a 1.0101

Coffea arabica, Coffee, Plants, Rubiaceae

Cof a 2

Coffea arabica, Coffee, Plants, Rubiaceae

Cof a 2.0101

Coffea arabica, Coffee, Plants, Rubiaceae

Cof a 3

Coffea arabica, Coffee, Plants, Rubiaceae

Cof a 3.0101

Coffea arabica, Coffee, Plants, Rubiaceae

 

The first allergen isolated from Coffea arabica was a class III chitinase with a molecular weight of 32 kDa (Cof a 1), which was identified in 3 out of 17 symptomatic coffee workers (18%) (13). Cof a 2 and Cof a 3 (9 and 7 kDa, respectively) are two cysteine-rich metallothioneins that have also been identified as coffee allergens. In a screening of 18 symptomatic coffee workers  8 (44%) had serum IgE antibodies to one of the two allergens (7, 14). 

Cross-reactivity

One study examined the cross-reactivity between  extracts of various coffee beans and dust as well as with castor bean, which is another suspected allergen in the coffee processing industry. However no evidence of cross-reactivity was found with the roasted coffee beans (15).

Compiled By

Author: RubyDuke Communications

Reviewer: Dr. Michael Thorpe

 

Last reviewed:January 2022

References
  1. Weldegebreal B, Redi-Abshiro M, Chandravanshi BS. Development of new analytical methods for the determination of caffeine content in aqueous solution of green coffee beans. Chem Cent J. 2017;11(1):126.
  2. Ferreira T, Shuler J, Guimarães R, Farah A. CHAPTER 1 Introduction to Coffee Plant and Genetics.  Coffee: Production, Quality and Chemistry: The Royal Society of Chemistry; 2019. p. 1-25.
  3. Gomes LC, Bianchi FJJA, Cardoso IM, Fernandes RBA, Filho EIF, Schulte RPO. Agroforestry systems can mitigate the impacts of climate change on coffee production: A spatially explicit assessment in Brazil. Agriculture, Ecosystems & Environment. 2020;294:106858.
  4. ITIS. Coffea L. (coffee) 2021 [cited 2021 15.11.21]. Available from: https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=35189#null.
  5. Wee JH, Yoo DM, Byun SH, Song CM, Lee HJ, Park B, et al. Analysis of the Relationship between Asthma and Coffee/Green Tea/Soda Intake. Int J Environ Res Public Health. 2020;17(20).
  6. Oñatibia-Astibia A, Martínez-Pinilla E, Franco R. The potential of methylxanthine-based therapies in pediatric respiratory tract diseases. Respir Med. 2016;112:1-9.
  7. Peters U, Frenzel K, Brettschneider R, Oldenburg M, Bittner C. Identification of two metallothioneins as novel inhalative coffee allergens cof a 2 and cof a 3. PLoS One. 2015;10(5):e0126455.
  8. Touati N, Chiriac AM, Bourrain JL, Demoly P. An Unusual Case of Occupational Rhinitis. J Investig Allergol Clin Immunol. 2020;30(3):207-8.
  9. Nakagawa Y, Odomari K, Kotobuki Y, Kiyohara E, Katayama I, Fujimoto M. Anaphylaxis caused by sodium caseinate contained in canned coffee. Allergol Int. 2020;69(1):157-8.
  10. Sugiyama K, Cho T, Tatewaki M, Onishi S, Yokoyama T, Yoshida N, et al. Anaphylaxis due to caffeine. Asia Pac Allergy. 2015;5(1):55-6.
  11. Younus F, Farah Younus H, Lateef I, Abdul E, Al-Layla E, Ghanim I. Food allergy in displaced people from Mosul City. Iranian Journal of Ichthyology. 2021;8.
  12. Allergome. Coffee 2021 [cited 2021 15.11.21]. Available from: http://www.allergome.com/script/search_step2.php.
  13. Manavski N, Peters U, Brettschneider R, Oldenburg M, Baur X, Bittner C. Cof a 1: identification, expression and immunoreactivity of the first coffee allergen. Int Arch Allergy Immunol. 2012;159(3):235-42.
  14. Raulf M. Allergen component analysis as a tool in the diagnosis and management of occupational allergy. Mol Immunol. 2018;100:21-7.
  15. Lehrer SB, Karr RM, Salvaggio JE. Extraction and analysis of coffee bean allergens. Clinical & Experimental Allergy. 1978;8(3):217-26.