title: Positive and negative aspects of green coffee consumption - antioxidant activity versus mycotoxins.
abstract: BACKGROUND
  The quality of coffee depends not only on the contents of healthy compounds but also on its contamination with microorganisms that can produce mycotoxins during development, harvesting, preparation, transport and storage.
  
  
  RESULTS
  The antioxidant activity of green coffee brews measured in this study by ABTS, DPPH and Folin-Ciocalteu assays showed that coffee extracts from Robusta beans possessed higher activity in all assays than extracts from Arabica beans. The occurrence of ochratoxin A and aflatoxins (B1, B2, G1 and G2) in green coffee beans was studied using liquid chromatography/mass spectrometry. Apart from mycotoxins, the content of ergosterol as a marker indicating fungal occurrence was also determined. Among aflatoxins, aflatoxin B1 was the dominant mycotoxin in coffee bean samples, with the highest level at 17.45 ng g-1. Ochratoxin A was detected in four samples at levels ranging from 1.27 to 4.34 ng g-1, and fungi potentially producing this toxin, namely Aspergillus oryzae, Alternaria sp., Aspergillus foetidus, Aspergillus tamarii and Penicillium citrinum, were isolated.
  
  
  CONCLUSIONS
  Steaming and decaffeination of coffee beans increased antioxidant activities of brews in comparison with those prepared from unprocessed beans. Although toxins can be quantified in green coffee beans and novel fungi were isolated, their concentrations are acceptable according to legal limits. © 2017 Society of Chemical Industry.
authors.affiliation: Institute of Chemistry and Technical Electrochemistry, Poznan University of Technology, Poznań, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Jeszka-Skowron
authors.affiliation: Institute of Chemistry and Technical Electrochemistry, Poznan University of Technology, Poznań, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Zgoła-Grześkowiak
authors.affiliation: Department of Chemistry, Poznań University of Life Sciences, Poznań, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Waśkiewicz
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Poznań, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Stępień
authors.affiliation: Institute of Chemistry and Technical Electrochemistry, Poznan University of Technology, Poznań, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Stanisz
mesh_terms: D000348:Aflatoxins / Q000032:analysis / Q000378:metabolism; D000975:Antioxidants / Q000032:analysis*; D001230:Aspergillus / Q000378:metabolism; D040503:Coffea / Q000737:chemistry* / Q000382:microbiology; D003069:Coffee / Q000737:chemistry* / Q000382:microbiology; D005506:Food Contamination / Q000032:analysis*; D009183:Mycotoxins / Q000009:adverse effects / Q000032:analysis*; D009793:Ochratoxins / Q000032:analysis / Q000378:metabolism; D010407:Penicillium / Q000378:metabolism; D012639:Seeds / Q000737:chemistry / Q000382:microbiology
chemical_list: D000348:Aflatoxins; D000975:Antioxidants; D003069:Coffee; D009183:Mycotoxins; D009793:Ochratoxins; C025589:ochratoxin A
keywords: antioxidant activity; ergosterol; fungal pathogens; green coffee beans; mycotoxins