Effect of Aspergillus flavus contamination on the inherent quality of Glycyrrhiza uralensis

Abstract

Glycyrrhiza uralensis is a common edible plant of the Chinese Materia Medica (CMM). Such a herb might be naturally contaminated with toxicogenic fungi producing various mycotoxins that can cause serious harm to humans. So far, studies have focused mainly on mycotoxin detection in CMM, but the effect of mycotoxin production on the inherent quality of CMM has not been investigated and elucidated. In the present study, sterilised G. uralensis was inoculated and incubated with Aspergillus flavus for several days to investigate the effect of aflatoxins accumulation on the inherent quality of G. uralensis. Changes in content of aflatoxin B1, B2, G1 and G2, and the herb's four bioactive components, i.e. glycyrrhizic acid, liquiritin apioside, liquiritin and liquiritigenin, were detected using ultra performance liquid chromatography coupled with fluorescence and photodiode array detection, respectively. The results showed that incubation of G. uralensis with A. flavus for 10 days resulted in the accumulation of aflatoxins, especially aflatoxin B1 and B2, and the reduction of the four bioactive components. From the negative correlation between the content of aflatoxins and bioactive components, it can be concluded that fungal contamination does not only result in harmful mycotoxins in CMM, but also influences its inherent quality.