###### Abstract  
The aim of the present research is the evaluation of the extraction process effect on the chemical composition, the antioxidant activities, and the mild steel corrosion inhibition ability of _Argania spinosa_'s extracts (alimentary oil (AO) and hexanic extract of roasted almonds (HERA)). The chemical composition revealed that both extracts have the same major compounds: Palmitic, linoleic, and stearic acids, with their order slightly different. Electrochemical impedance spectroscopy (EIS), weight loss measurements, and polarization curves were used to estimate AO and HERA's mild steel corrosion's inhibition capacity. Based on these three methods, AO registered, respectively, 81%, 87%, and 87% inhibition efficiency while HERA registered 78%, 84%, and 82% inhibition efficiency. The antioxidant activity of AO and HERA was examined in parallel with standard antioxidants (gallic acid and quercetin) using two assays: DPPH* scavenging assay and ferric reducing antioxidant power assay (FRAP). AO had less EC\({}_{\text{S0}}\) in both techniques (DPPH*: \(3559.08\pm 161.75\,\text{\mu g/mL}\); FRAP \(1288.58\pm 169.21\,\text{\mu g/mL}\)) than HERA (DPPH*: \(3621.43\pm 316.05\,\text{\mu g/mL}\); FRAP \(1655.86\pm 240.18\,\text{\mu g/mL}\)). Quantum chemical and molecular dynamic studies were employed to suggest the adsorption mechanism.  
Argania spinosa; chemical composition; corrosion; mild steel; antioxidant activity; molecular dynamic simulation +
Footnote †: journal: Applied Sciences  
Thanks to its various mechanical proprieties, mild steel is widely used in the industrial field. By 2019, the world total steel production was estimated to be 1.9625 billion tonnes and in 2020, the United Kingdom economy gained GBP 2.0 billion in terms of gross value added (GVA) [6]. These statistics show the importance of mild steel in human lives. However, iron alloys in general are not stable and exhibit lower corrosion resistance than other aluminum and copper alloys [6; 7]. According to a benchmark study released in 2002 by the US Federal Highway Administration (FHWA), this natural process, corrosion, represents 3.1% of the annual US gross domestic product (GDP) [8]. Among the solutions provided to solve this problem or at least decreases its damages we find the use of plant extracts to be eco-friendly corrosion inhibitors [9]. Different plant parts, such as roots, seeds, flowers, barks, leaves, and fruits, were used to extract potential corrosion inhibitors either by maceration and Soxhlet (for extraction by organic solvents) or hydro-distillation (for essential oils extraction). These extracts were tested as corrosion inhibitors for mild steel in acidic media and showed remarkable inhibition efficiencies [10; 11; 12; 13; 14; 15; 16]. The use of these plant parts as corrosion inhibitors is an added value to the plant and a chance to valorize it when it could be an invasive species and locals are having a hard time to stop it spread in nature.  
Several studies showed that the chemical composition of organ oil depends not only on the extraction method used but also on the origin of kernels (climatic conditions of the area) and the storage condition [17]. Since the chemical composition is related to the origin of the kernel, this work aims to present the chemical composition of organ oil (AO) and the hexanic extract of roasted almonds (HERA) from a small village, Lagffate in Taroudant, in order to provide data that can be compared with other results from other places. This work also aims to evaluate, experimentally and theoretically, the antioxidant and corrosion inhibition effects of two extracts from _Argania spinosa_'s almonds.