Isolement et identification des champignons associés au stockage des fruits secs commercialisés dans la région d’El Oued (Algérie)

Abstract

Dried fruits represent an important staple food in Algeria, particularly in the El Oued region, due to their high nutritional value and their widespread consumption during various festive occasions. The present study aimed to evaluate the fungal contamination of dried fruits marketed in the El Oued region (dates, figs, raisins, almonds, and walnuts) and to determine the relationship between the nature of the product and the fungi associated with storage.A total of ten samples were subjected to microbiological analysis using direct and indirect isolation methods on Sabouraud culture medium and incubated at 28°C. Identification of the isolates, based on their macroscopic and microscopic characteristics, revealed four main fungal genera: Aspergillus niger, the most frequently isolated species; Penicillium chrysogenum, detected exclusively in almonds; Rhizopus stolonifer, isolated from figs and Deglet Nour dates; and Mucor sp., identified in a white fig sample.The results showed that oil-rich dried fruits (almonds and walnuts) were mainly contaminated by Penicillium and Aspergillus, fungi adapted to low water activity conditions. In contrast, sugary dried fruits (figs, dates, and raisins) favored the growth of fast-growing fungi such as Rhizopus and Mucor, which benefit from residual moisture and high sugar content. These contamination levels, likely related to inadequate storage conditions such as inappropriate temperature, excessive humidity, and insufficient ventilation, may pose a potential health risk since most of these molds are capable of producing mycotoxins. The study recommends improving storage practices and implementing strict sanitary controls before direct consumption. In light of these findings, strengthening preservation measures and establishing rigorous quality control systems are essential to ensure the safety and quality of dried fruits intended for human consumption.