Antioxidant and antibacterial activities of green oak acorn (Quercus ilex) from Algeria

Abstract

In addition to the nutritional value of green oak acorns they have also differ-ent biological properties. The object of this research is to examine the anti-oxidant and antibacterial activities of almond, tegument and pericarp of green oak acorn (Quercus ilex) from Algeria. Four methods were used to evaluate the antioxidant activity, with analysis of Phenolic compound, as well as the study of antibacterial activity. The analysis of acorn shows different levels of total polyphenols, flavonoids, and condensed tannins in its three compounds where the pericarp and tegument have high levels compared to the almond. The extract of pericarp showed the highest antioxidant activity to trap the DPPH radical (IC50: 86.37 μg/ ml), inhibit β-carotene bleaching (RAA = 90.19 %) and reduce molybdenum (TAA: 467.57 AAE/100g of extract), whereas the tegument has a strong ability to give hydrogen to reduce iron. In addition, the pericarp of acorn was efficient to inhibit growth of pathogenic bacteria, mostly against Bacillus cereus and Staphylococcus aureus, with the lowest Minimum Inhibitory and Bactericidal Concentrations. These results confirm the importance of consumption of green oak acorns (Quercus ilex) and signify that they are an excellent source of natural antioxidants and antibacterial compounds, which could be exploited in pharmaceutic, cosmetic and agri-food sectors.