JOURNAL OF COSMETIC SCIENCE 86 components, as sterols, participate in argan oil cosmetic activity (4). In our physico- chemical analyses indicating a 6-month-limit for argan oil stored at 25°C, we compared the FA and sterol composition of argan oil just after pressing and after 6 months. No signifi cant difference was observed for sterol or FA composition after this period (Table I). Such chemical stability suggests that the dermocosmetic properties of argan oil are fully preserved during the fi rst 6 months of its storage when performed at 25°C. SUMMARY Cosmetic argan oil is often presented as possessing low preservation properties. Storage at various temperatures demonstrate that when argan oil is stored at temperatures up to 25°C its quality can be easily ascertained for 12 months according to the Moroccan norm, and for 6 months according to the cosmetic industry norm. Formation of oxidative spe- cies is the main reason for argan oil instability, far ahead from triglyceride hydrolysis or sterol loss. Storage of argan oil under inert atmosphere or/and at low temperature should increase argan oil shelf life if necessary. To increase argan oil shelf life, the addition of antioxidants could also be considered, but the resulting product would not satisfy the “extra virgin argan oil” labeling anymore. REFERENCES (1) T. J. Lybbert, A. Aboudrare, D. Chaloud, N. Magnan, and M. Nash, Booming markets for Moroccan argan oil appear to benefi t some rural households while threatening the endemic argan forest. Proc. Natl. Acad. Sci. USA, 108, 13907–13912 (2011). (2) Z, Charrouf and D. Guillaume, Should the Amazigh diet (regular and moderate argan-oil consumption) have a benefi cial impact on human health? Crit. Rev. Food Sci. Nutr., 50, 473–477 (2010). Table I Sterol and Fatty Acid Composition of Cosmetic Argan Oil Immediately after Cold-Pressing and after 6 Months (1 Year) of Storage Sunlight-Exposed or -Protected Initial 25°C Exposed Protected Sterol (%) Schottenol 46.6 ± 2.5 46.5 ± 3.9 (47.8 ± 4.1) 47.5 ± 3.5 (46.2 ± 2.5) Spinasterol 39 ± 2 36 ± 4 (38.1 ± 6.2) 37 ± 3 (40 ± 4) Stigma-7a 4.2 ± 0.8 5 ± 2 (4.1 ± 1.5) 5 ± 1 (4.3 ± 2.1) Stigma-8a 3.9 ± 0.6 4.1 ± 0.9 (3.8 ± 1.1) 3.8 ± 0.7 (4 ± 1) Campesterol 0.2 ± 0.1 0.1 ± 0.1 (0.2 ± 0.1) 0.2 ± 0.1 (0.2 ± 0.1) Fatty acid (%) Palmitic 13.2 ± 1.5 13.2 ± 1.8 (13.1 ± 2.1) 13.1 ± 2.5 (13.2 ± 1.8) Stearic 5.3 ± 0.4 5.6 ± 0.9 (5.5 ± 1.1) 5.2 ± 0.7 (5.7 ± 1.5) Oleic 48 ± 3 48 ± 4 (48 ± 6) 47 ± 4 (48 ± 4) Linoleic 33 ± 2 33 ± 2 (33 ± 4) 32 ± 2 (33 ± 4) Linolenic 0.1 ± 0.1 0.1 ± 0.1 (0.1 ± 0.1) 0.1 ± 0.1 (0.1 ± 0.1) a Stigma-7: Stigma-7,24-dien-3-ol, Stigma-8: Stigma-8,22-dien-3β-ol.

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