Study of aflatoxin B1 production by Aspergillus parasiticus in bee pollen of Greek origin

Abstract

Aflatoxin B1 (AFB1) is a carcinogenic metabolite produced by certain Aspergillus species such as A. parasiticus and A. flavus. The beneficial properties of bee pollen have transformed this commodity into an increasingly frequent component of the human diet. As bee pollen is a substrate on which aflatoxigenic fungi can grow, AFB1 production is likely. In the present study, we describe a method for aflatoxin B1 determination in bee pollen utilising high pressure liquid chromatography (HPLC) with a fluorescence detector (FD). The recovery factor of the method was found to be 111% (RSD% 1.61), while the detection limit (LOD) was 0.08ng AFB1/g. An additional aim of this study was to investigate the growth of A. parasiticus and AFB1 production in bee pollen. Results indicated that no mycelial growth was observed and no AFB1 was detected in bee pollen samples containing natural microbiota throughout the entire observation period (20days). In contrast, AFB1 production in treated bee pollen samples (15g pollen/flask) inoculated with A. parasiticus was significantly higher (p ≤ 0.05) compared to control samples (treated but not inoculated) throughout the entire incubation period, while no mycelial growth was apparent. Maximum production was observed on the 12th day (79.29ng AFB1/flask and 32.44ng AFB1/flask for inoculated and non-inoculated bee pollen, respectively). As a result, AFB1 production in bee pollen is likely even following a minor contamination, which could occur randomly.