Ochratoxin A and citrinin in green coffee and dietary supplements with green coffee extract

Abstract

The aim of this study was to determine the degree of mold contamination and mycotoxin levels in commercially available green coffee products and dietary supplements with green coffee extract. The study included 34 samples from green coffee products: raw beans (n = 16), ground coffee (n = 15) and instant coffee (n = 3), as well as 22 samples from dietary supplements in form of capsules (n = 19), tablets (n = 2) and sachets (n = 1). Total mold count was determined with spread-plate method. Anamorphic mold were identified based on their microscopic morphology and the type of sporulation. Concentrations of mycotoxins, ochratoxin A and citrinin, were quantified by means of HPLC-fluorescence detection. Molds, typically Aspergillus spp. and Penicillium spp., were found in 94% of green coffee beans, 100% of ground and instant coffee samples, and 55% of dietary supplement samples. None of the samples contained detectable levels of citrinin. Ochratoxin A (0.4 ng/g) was detected in only one sample of raw green coffee beans, but in up to 40% and 67% of ground and instant coffee samples, respectively. Mean concentrations of ochratoxin A in ground and instant coffee samples were 3.28 ng/g and 4.09 ng/g, respectively, and maximum concentrations amounted to 6.65 ng/g and 7.44 ng/g, respectively. Ochratoxin A (mean concentration 9.60 ng/g, maximum level 31.4 ng/g) was also detected in up to 58% of the supplement capsules, but in none of tablets and sachets.