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 degrees C) and time (from 10 to 50 min), on oil yield, contents in total phenolic compounds, alpha- and gamma-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 degrees 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, alpha- and gamma-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.