Fungal contamination of food commodities in Durban, South Africa

The study investigated the occurrence of natural fungal contaminants in food commodities consumed in Durban, South Africa. A total of 110 samples including Bambara groundnut, maize and maize-derived products, rice, and spices were collected from open markets and retail stores and screened for fungal contaminants using conventional and molecular methods. A total of 179 isolates belonging to fungal genera including Aspergillus, Penicillium, and Fusarium were recovered. Aspergillus (52.5%) and Penicillium (31.8%) were the most prevalent genera, contaminating 85.5% and 51.8% of the total samples analyzed, respectively. Bambara groundnut (100%), spices (89.5%), rice (86.9%), and maize and maize-derived products (71.9%) were contaminated by Aspergillus sp. Bambara groundnut (64.7%) and spices (44.7%) were contaminated by Aspergillus flavus. Penicillium citrinum was recovered from spices (71.1%), Bambara groundnut (61.7%), rice (34.8%), and maize and maize-derived products (31.3%). Some of the isolated fungi are mycotoxin producers and their detection raise concerns on consumers' health. Practical applications: Fungal contamination of agricultural products poses a challenge to global food security. Mycotoxins, the toxigenic metabolites produced by some fungal species, are not completely destroyed by processing operations, and are carried over into processed food, through which they may cause harm to consumers. Routine tests on the mycological quality of consumer goods have therefore become pertinent. This study reports the isolation of live pathogenic fungi in commonly consumed food commodities, necessitating the need for regular routine checks to ensure the mycological safety of agricultural products offered for sale to consumers. As proliferation of these fungi is influenced by storage conditions, this study will also contribute to devising appropriate storage management techniques for these commodities.