Antifungal Activity Evaluation of White and Red Grape Pomace Extracts Against Some Phytopathogens

The main objective of this research is to assess the antifungal activity of grape pomace extracts of four local varieties (i.e., two white, Fetească Albă and Tămâioasă Românească, and two red, Fetească Neagră and Negru de Drăgășani), knowing their valuable chemical profile. The antifungal activity of the extracts was evaluated using two fungi strains (Aspergillus niger and Alternaria alternata). Despite the classical extraction method, using absolute ethyl alcohol (99–100%): water=1:1 as a solvent, the obtained grape pomace extracts presented high antifungal effectiveness. Thus, Tămâioasă Românească (TR), Fetească Neagră (FN), Fetească Albă (FA), and Negru de Drăgășani (ND) pomace extracts were shown to have superior antimicrobial activity against Aspergillus niger due to their higher concentration of polyphenols. On the other hand, FN and ND extracts did not exhibit antifungal activity against Alternaria sp., although the growth inhibition efficiency was lower compared to the growth inhibition of Aspergillus sp. In conclusion, this study emphasized a strong correlation between the antifungal activity of analyzed grape pomace extracts and their excellent antioxidant potential.