Mineral Composition, Physicochemical Characteristics, and Antioxidant and Antibacterial Properties of Oil Extracted...

Apricot kernels, often regarded as by-products, are a valuable source of oils and bioactive compounds such as polyphenols, which have applications in pharmacology, the food industry, and cosmetology. This study aimed to address the research gaps regarding the nutritional and functional potential of Moroccan bitter apricot kernels (BAKs) by analyzing their mineral composition and evaluating the physicochemical, antioxidant, and antibacterial properties of their oil. The mineral composition of the kernels was analyzed using ICP-AES. The physicochemical properties of BAK oil, including density (D), acid value (AV), saponification number (SN), iodine value (IV), refractive index (RI), and peroxide value (PV), were evaluated. The total phenolic content (TPC) and total flavonoid content (TFC) were estimated using the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant potential was examined through 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and total antioxidant capacity (TAC) assays, and antibacterial activity was evaluated using disc diffusion and microdilution methods. Results showed that the apricot kernels are rich in essential minerals, with high amounts of potassium (184.75 ± 5.5 g/kg) and phosphorus (109.72 ± 2.5 g/kg). The physicochemical properties of the studied oil were as follows: D: 0.92 ± 0.001 g/cm³, AV: 0.65 ± 0.17 mg KOH/g of oil, SN: 187.15 ± 0.05 mg KOH/g of oil, IV: 95.5 ± 0.45 g I₂/100 g of oil, RI: 1.470 ± 0.001, and PV: 0.98 ± 0.17 meq O₂/kg of oil. The total phenolic and flavonoid contents were 41 ± 0.5 mg GAE/100 g and 23.1 ± 0.2 mg QUE/100 g of oil, respectively. The DPPH IC₅₀ value was 6640 ± 0.32 μg/mL, and the TAC was 2.21 ± 0.12 mg AAE/g of oil. The highest antibacterial effect was observed against both Gram-positive bacterial strains, with a MIC value of 100 μL/mL. This study demonstrates that BAKs are a noteworthy oil source, offering promising opportunities for applications in the food and pharmaceutical industries.