Optimum roasting conditions of argan kernels (Argania spinosa L.) for the production of high-quality edible argan oil

Roasting is an important step in the production of edible argan oils. The effect of argan kernel roasting temperature (ranging from 150 to 200 °C) and time (from 10 to 50 min), on oil yield, contents in total phenolic compounds, α- and γ-tocopherol, and oxidative stability, was researched using response surface methodology. Increases in roasting temperature and time have a significant effect on all the responses. This study showed that the optimum roasting conditions of argan kernel (indirect heat by convection) for the production of edible argan oils were 150 °C and 50 min, which allowed reaching a maximum oil yield of 32.45%. Edible argan oil, obtained under these conditions, had a content of total phenolic compounds of 78.01 mg/kg, α- and γ-tocopherol of 30.28 and 495.03 mg/kg, respectively, and an oxidative stability of 37.58 h. Furthermore, it presented olfactory notes of ‘almond, dried fruits, hazelnut and waffle’, with ‘sweet’ and ‘fruity’ as positive attributes, without any defect.