Analysis and antioxidant capacity of the phenolic compounds from argan fruit (Argania spinosa (L.) Skeels)

Polyphenol composition of the shell, pulp, roasted, and unroasted kernels of the argan fruit was qualitatively and quantitatively determined by HPLC coupled with electrospray negative ionization ion trap mass spectrometry (HPLC-ESI-MS). Eleven phenolic compounds were identified. Unroasted kernels and shell contained various polyphenols but the pulp was characterized by a very high amount of total polyphenols (75.78 mg of gallic acid equivalent/g). The radical scavenging (DPPH• method) and antioxidant activity (ABTS method) of each fruit part was also determined. Argan fruit pulp showed the highest radical scavenging activity (0.17 ± 0.005 µM Trolox equivalent/mg) and antioxidant activity (0.375 ± 0.07 µM Trolox equivalent/mg). Therefore, argan fruit polyphenols are good candidates to be exploited as health supplements and nutraceuticals.