Résumé:
The aim of this study is the evaluation of antifungal activity of polyphenols extracted from two varieties of dry bean, presenting white (Tima) and red (MGT djedida) color. Determination of moisture for the two varieties showed that these grains are favorable for moulds growth. Purification and microscopic study of the isolated stocks allowed the identification of 6 moulds genera: Alternaria, Aspergillus, Moniliella, Fusarium, Penicillium and Rhizopus. Extraction of total polyphenols was carried by a polar solvent and their quantification was based on the reaction of Folin Ciocalteu. The total polyphenolic content was 0,40±0,005 mg EAG/g for the red variety and 0,27±0,005 mg EAG/g for the white variety. The antifungal activity carried by the methods of direct contact, dilution, and antifungal index (IA100) made possible to prove the antifungal capacity of polyphenols, most sensitive stocks are Alternaria sp., Moniliella sp. and Rhizopus sp.. The most active polyphenols are the red healthy bean polyphenols. Among this study, we can show that the promising results obtained incent creation of varieties with high percentage of polyphenols, preservative, bio-effective and natural agents, which can be an alternative solution for chemical agents used for the protection of harvests in storage structures.
