Fungal Contamination and Physicochemical Analysis of Algerian Dried Fig Varieties: Assessment of Aflatoxins and Ochratoxin A Levels

Abstract

The fig (Ficus carica L.) is a nutritionally valuable fruit, rich in fiber, minerals, vitamins, and carbohydrates. In Algeria, dried figs are widely consumed. This study evaluated the physicochemical characteristics and fungal contamination of dried figs from two local varieties: “Thaamriouth” and “Abarkan”. The methods used for fungal identification included direct plating on DG18 medium, purification of fungal isolates, and molecular identification of species using polymerase chain reaction (PCR). Contamination levels were quantified using high-performance liquid chromatography with a fluorescence detector (HPLC/FLD). Physicochemical analyses measured protein and carbohydrate content, water activity, pH, and titratable acidity to assess the suitability of dried figs as a micro-ecosystem for contamination by aflatoxigenic and ochratoxigenic fungi. Results showed that Aspergillus section Nigri was the most frequently isolated fungal group, detected in 70% of samples. Less common isolates included Mucorales (15%), Penicillium (10%), while the remaining 5% comprised Aspergillus section Flavii. The high carbohydrate content and acidic pH appeared to increase the figs’ susceptibility to fungal contamination. HPLC/FLD analysis revealed no detectable levels of aflatoxins and ochratoxin A. PCR identification confirmed the presence of Aspergillus niger and A. awamorii. Despite the absence of detectable aflatoxins and ochratoxin A in the fig samples, the potential risk to human health cannot be ruled out, particularly due to the presence of toxigenic fungal species. Therefore, proper agricultural and storage practices remain essential