Influence of roasting and seed collection on argan oil odorant composition

Abstract

Argan tree (Argania spinosa (L.) Skeels) is endemic in Morocco. The aroma compounds of argan oil prepared from roasted and unroasted argan kernels were analyzed using GC-MS and olfactometry. Influence of the fruit peeling method on the olfactometric parameters was also studied. Oil coming from unroasted kernels furnished fourteen compounds if the fruits had been mechanically-peeled fruits (uRK), and twenty two when the kernels had been goat digested (GuRK). Thirteen compounds were common to the two studies. The oil obtained from roasted kernels of mechanically-peeled fruits (RK) furnished nineteen compounds. Twenty one were isolated from the oil obtained from roasted kernels of goat digested fruits (GRK). Twelve compounds were common to the two analyses. In all oil samples, the aldehyde/ketone derivatives composed the largest group of odorants. Acetophenone and p-methylacetophenone appear to be the most important contributors to the RK oil aroma. The unpleasant smell presented by argan oil prepared from naturally-peeled argan fruits (GuRK, GRK) could result from the presence of one or two odorants presenting a rancid odor.