A review on the utilization of the by-products generated during the production of Argan oil

The annual production of argan oil reaches approximately 4450 tons, which inevitably generates a large quantity of by-products. From the point of view of argan oil production, the pulp, the nutshell and the press cake represent approximately 97 % of the weight of the fruit, while only the kernels, weighing approximately 6 kg per 100 kg of dried fruit, are used to produce argan oil. Such quantity of kernels makes 3 L of argan oil. Most often, by-products resulting from argan oil production are not used industrially and are considered waste. Valorizing those inherently produced by-products is necessary to increase sustainability competitiveness and lessen the impact of the argan oil industry on the environment. This review aims to present an overview of the by-products generated during the production of argan oil, examine current valorization approaches and discuss the prospects for improving their future valorization. The valorization of argan nutshell is one of the most advanced and promising areas, positioning this residue as a sustainable resource that enhances the profitability of the argan oil sector. Their utilization in the production of CO2-based activated charcoal and biofuels further promotes their value and sustainability. Overall, this review highlights the growing interest in argan by-products in recent years, and the emergence of numerous value-adding applications in the fields of bioenergy, nanomaterials, pharmaceutical and cosmetics industries.