Antioxidant and antimicrobial activities of bitter and sweet apricot (Prunus armeniaca L. ) kernels

ABSTRACT

The present study describes the in vitro antimicrobial and antioxidant activity of methanol and water extracts of sweet and bitterapricot (Prunus armeniaca L.) kernels. The antioxidant properties of apricot kernels were evaluated by determining radicalscavenging power, lipid peroxidation inhibition activity and total phenol content measured with a DPPH test, the thiocyanatemethod and the Folin method, respectively. In contrast to extracts of the bitter kernels, both the water and methanol extracts ofsweet kernels have antioxidant potential. The highest percent inhibition of lipid peroxidation (69%) and total phenolic content (7.9± 0.2 μg/mL) were detected in the methanol extract of sweet kernels (Hasanbey) and in the water extract of the same cultivar,respectively. The antimicrobial activities of the above extracts were also tested against human pathogenic microorganismsusing a disc-diffusion method, and the minimal inhibitory concentration (MIC) values of each active extract were determined. Themost effective antibacterial activity was observed in the methanol and water extracts of bitter kernels and in the methanol extractof sweet kernels against the Gram-positive bacteria Staphylococcus aureus. Additionally, the methanol extracts of the bitterkernels were very potent against the Gram-negative bacteria Escherichia coli (0.312 mg/mL MIC value). Significant anti-candidaactivity was also observed with the methanol extract of bitter apricot kernels against Candida albicans, consisting of a 14 mm indiameter of inhibition zone and a 0.625 mg/mL MIC value.