Prevalence of toxigenic fungi in common medicinal herbs and spices in India

Mycotoxins are unavoidable contaminants of food grains, feeds, medicinal herbs, and spices, posing as health threat to animals and humans. The objective of this study was to screen medicinal herbs and spices for fungi and mycotoxin contamination and evaluate their safety. Sixty-three samples were examined for fungal contamination and fungal load determined using standard microbiological method. Aflatoxin and citrinin were detected using thin layer chromatography and high-performance chromatography technique. Fifty-eight out of the 63 samples were contaminated, while five were free from fungal contamination. Analysis revealed that 47 % of the samples had a fungal load above 1 × 103 cfu/g which is the permissible limit set by World Health Organization. The samples Mesua ferrea-II and Terminalia chebula-III had the highest fungal load, i.e., 5.0 × 104 cfu/g. A total of 187 fungi were isolated, out of which 28 were toxigenic which included 19 aflatoxin-producing Aspergillus flavus and 9 citrinin-producing Penicillium citrinum. The natural contamination with aflatoxin B1 was detected only in one sample, i.e., Arachis hypogaea (groundnut) which was present beyond the permissible limit. Though toxigenic fungi were isolated, mycotoxins were not detected from any of the medicinal herbs and spices. Medicinal herbs and spices are susceptible to toxigenic fungi; however, they also possess intrinsic factors that inhibit mycotoxin contamination. This study provides a basis in assessing the degree of fungal and potential mycotoxin contamination in medicinal herbs and spices. Electronic supplementary material The online version of this article (doi:10.1007/s13205-016-0476-9) contains supplementary material, which is available to authorized users.