Mycological quality and mycotoxin contamination of Sri Lankan peppers (Piper nigrum L.) and subsequent exposure assessment

- Characterization of the toxigenic moulds in peppers of Sri Lankan origin.
- Aspergillus flavus, Aspergillus parasiticus, Aspergillus niger and Penicillium ssp. were the frequent moulds.
- Aflatoxins, ochratoxin A, fumonisin B1, sterigmatocystin and citrinin were found.
- High frequency of the carcinogen sterigmatocystin in peppers reported first time.
- Occurrence data of diverse mycotoxins can be very useful for exposure assessment.

The aim of the study was to characterize the toxigenic moulds and to screen different mycotoxins in peppers (Piper nigrum L.) of Sri Lankan origin. Aspergillus flavus, Aspergillus parasiticus, Aspergillus niger and Penicillium spp. were found to be the most dominant fungi. Characterization of the moulds was carried out in A. flavus and parasiticus agar (AFPA) and malt extract agar (MEA) in 77 black pepper (BP) and 11 white pepper (WP) samples. In total, 73% of the BP and 64% of the WP samples were contaminated with A. flavus and/or A. parasiticus (AfAp). A BP sample with water activity (aw) 0.70 recorded the highest count of AfAp (4.3*104 CFU/g). Moreover, 75% of the BP samples exceeded the safe aw limit (0.65) set by the European Spice Association (ESA). The frequency of occurrence of A. niger in BP was 62% with counts up to 1.3*103 CFU/g. Penicillium spp. were found in 61% and 55% of the BP and WP samples, respectively. In BP 94% of the samples had a Penicillium contamination below 103 CFU/g. Other Aspergillus spp, found in peppers included, Aspergillus terrus, Aspergillus tamarii, Aspergillus candidus, Aspergillus penicilloides, Aspergillus sydowii and Aspergillus fumigatus. Mould counts in BP (102-104 CFU/g) were significantly higher than that of WP (<102 CFU/g). Apart from the occurrence of “classical mycotoxins” of spices, aflatoxins (