Aspergilli and ochratoxin A in coffee

Paramee Noonim, Warapa Mahakarnchanakul, János Varga, Robert A. Samson

Research output: Chapter

2 Citations (Scopus)


Ochratoxin contamination of coffee can be regarded as a post-harvest problem. The diversity and ochratoxin producing potential of Aspergilli in coffee beans depends on a combination of various factors including coffee variety, geographic region, climate, susceptibility to insect pests and processing method. According to recent surveys, the most important ochratoxin producers are A. westerdijkiae and A. niger in Arabica coffee beans, and A. carbonarius in Robusta beans. Optimum water activities and temperatures for growth and ochratoxin production of Aspergillus species were found to be at aw 0.95-0.99 at 24-31 °C. Some chemicals (caffeine, chlorogenic acid) have inhibiting effect on growth and toxin production of Aspergillus species in coffee. During storage, water activities above 0.80 pose a risk for fungal growth and ochratoxin contamination until roasting. In order prevent the risk of ochratoxin contamination, this critical period need to be minimised to appropriate levels to prevent growth and toxin production. The choice of coffee processing affects ochratoxin content in coffee, while roasting can reduce ochratoxin levels by 30-96% depending on temperature and time of roasting. Coffee contributes only to a small extent to ochratoxin intake of humans in Europe, even if it is prepared from relatively highly contaminated green beans.

Original languageEnglish
Title of host publicationAspergillus in the Genomic Era
PublisherWageningen Academic Publishers
Number of pages19
ISBN (Print)9789086860654
Publication statusPublished - dec. 1 2008


ASJC Scopus subject areas

  • Social Sciences(all)
  • Immunology and Microbiology(all)

Cite this

Noonim, P., Mahakarnchanakul, W., Varga, J., & Samson, R. A. (2008). Aspergilli and ochratoxin A in coffee. In Aspergillus in the Genomic Era (pp. 213-231). Wageningen Academic Publishers.