Occurrence of Ochratoxigenic Fungi and Ochratoxin A in Green Coffee from Different Origins

Abstract

Fungal infection and ochratoxin A (OTA) contamination were determined in green coffee samples from different origins, in which OTA-producing fungi were also identified. About 72% of the beans analysed by direct plating presented fungal infection, including species of Aspergillus, Penicillium and Rhizopus. The genus Aspergillus was presented in more than 90% of infected coffee beans. Aspergillus ochraceus and Aspergillus section Nigri isolates represented 2.8 and 65.4%, respectively from the total number of isolates from the coffee beans. The capacity to produce OTA was determined in 260 isolates of A. section Nigri and 19 of A. ochraceus by the agar plug method, giving positive results for 6% of the A. section Nigri isolates and 16% of the A. ochraceus. OTA production was analysed by high performance liquid chromatography. OTA contamination of green coffee beans was analysed by enzyme immunoassay. OTA levels in all samples analysed were above the limit of detection (0.6 mg/kg), with a mean OTA concentration of 6.7 mg/kg.

Incidence and distribution of filamentous fungi during fermentation, drying and storage of coffee (Coffea arabica L.) beans

“…Several studies have reported the occurrence of toxinproducing fungi and ochratoxin in green coffee beans (4,18,20,26,28). A survey on stored green coffee beans from various origins has shown that coffee samples from African origin have significantly higher levels of OTA than those from America and Asia (21). The aim of this work was to detect the occurrence of filamentous fungi present in the different stages of coffee production by natural method including harvest, fermentation, drying and storage of beans.…”

Development and validation of a method for detection and quantification of ochratoxin A in green coffee using liquid chromatography coupled to mass spectrometry

“…After that, the IA column was washed with 10.0 mL of Milli-Q water at the same flow rate in green coffee of 15 ng.g -1 will result in a finished product that does not exceed the EU maximum limits (FOOD..., 2010). Several methods have been described for determining OTA in food matrix such as thin layer chromatography, spectrofluorometry, enzyme-linked immunosorbent assay, high performance liquid chromatography and liquid chromatography-mass spectroscopy (ALMEIDA et al, 2007;MASOUD;KALTOFT, 2006;PRADO et al, 2000;GILBERT;ANKLAM, 2002;PARDO et al, 2004;AHMED et al, 2007;SUGITA-KONISH et al, 2006). Reviewing the process it can be said that: the toxin is usually extracted with water, organic solvents, salt aqueous solution and acids or several mixtures.…”

Development and validation of a method for the analysis of Ochratoxin A in roasted coffee by liquid chromatography/electrospray-mass spectrometry in Tandem (LC/ESI-MS/MS)

“…26,27 Several techniques have been described for determining OTA in food matrix using thin-layer chromatography (TLC), gas chromatography (GC), enzyme-linked immunosorbent assay (ELISA), high performance liquid chromatography with fluorescence detector (HPLC-FLD) and liquid chromatography-mass spectroscopy (LC/ MS). 7,16,19,[28][29][30][31] The Official Methods of Analysis of AOAC International (AOAC) recomends a method for the determination of OTA is based on TLC and HPLC-FLD. Method proposed by Ministério da Agricultura, Pecuária e Abastecimento (MAPA) is based on HPLC--FLD.…”

“…13,34,35 Validation procedures of analytical method are necessary for legislation implementation to show that the method produces reliable results, provide accurate and reproducible results for monitoring and risk-assessment studies. 3,29 The absence of available Certified Reference Material (CRM) of OTA in roasted coffee is also an issue related to the validation of methods. 5,28 Due to the possible risk of Ocratoxina A as a contaminant in coffee (human health problem), as well as the important role of this product in the world´s economy, there is a strong need of a validated method in this area that could be used by coffee-producing and -exporting countries to check the compliance of consignments with criteria set by importing countries.…”