Comparative Analysis of Tunisian Wild Crataegus azarolus (Yellow Azarole) and Crataegus monogyna (Red Azarole) Leaf, Fruit, and Traditionally Derived Syrup: Phenolic Profiles and Antioxidant and Antimicrobial Activities of the Aqueous-Acetone Extracts

Quantitative and qualitative analyses of the yellow and red azarole phenolic extracts prepared from leaf, fruit peel/pulp, and syrup were comparatively investigated. The yellow azarole was found significantly richer in polyphenols than the red-fruit species. Hyperoside was the main phenolic in both yellow and red azarole leaves and only in yellow fruits, whereas procyanidin B2 was the major compound in red fruits. Yellow azarole leaf and fruit peel extracts exhibited the strongest antioxidant activities using DPPH (approximate to 168 and 79 mu mol TEAC/g fw, respectively) and FRAP (approximate to 378 and 161 mu mol Fe2+/g fw, respectively) assays. The highest antibacterial activities were recorded for the yellow azarole leaf and fruit peel extracts, especially against Staphylococcus aureus and Streptococcus faecalis. The low phenolic content of the syrups contrasted with their significant antioxidant and antimicrobial potentials, which were correlated to their hydroxymethylfurfural (HMF) (furan derivative amounts) content.