Growth Characterization of Mycotoxigenic Molds Isolated from Bread Flour Consumed in Algeria

Background: Cereals, including soft wheat, are widely consumed in Algeria because of the high demand for bread. Given the low water availability in baking flour, molds are most likely to grow and some are toxigenic, which may affect the quality of this product. The objective of this work was to determine and evaluate the fungal flora of bakery flour as well as to highlight its mycotoxigenic power and growth ability. Methods: A total of 241 samples were collected from different places in the western Algerian region. The enumeration was carried out according to Algerian standard regulation. The obtained fungi were identified basing on microscopic identification. After identification the Aspergillus and Penicillium genera were tested for the mycotoxins production on Y.E.S medium following by TLC revelation. As for the growth study, the growth was tested on PDA medium than adjusted by Barany’s model. Result: Mold enumeration revealed an overall contamination rate of 97.93% with concentrations (cfu/g) ranging from 1 to 15 log cfu/g. The identification of fungal genera revealed the presence of eleven genera of molds, namely, Penicillium sp. (69.29%), Cladosporium sp. (56.85%), Microsporum sp. (51.04%), Aspergillus sp. (34.85%), Auerobasidium sp. (24.07%), Exopiala sp. (21.58%), Mucor sp. (17.43%), Trichothecium sp. (9.13%), Trichoderma sp. (8.71%), Streptomyces sp. (2.07%) and Trichosporon sp. (0.41%). Only the genera Aspergillus and Penicillium showed a mycotoxins production reveal by the TLC method on YES media. The simulation of growth during storage at the bakery showed a remarkable increase that exceeded the threshold (4 log) for each genus and a significant increase (P less than 0.001). These results are of great industrial interest for improving the quality and reducing the risk linked to the consumption of the product.