The cultivation of the date palm (Phoenix dactylifera L.) is the main activity and source of livelihood for people from arid and semiarid regions of the world. Date production is increasing every year. In addition, pitted date exportation is rising and great amounts of date seeds are produced. This biomass represents a problem for manufacturing companies. At the moment, date seeds are normally discarded or used as animal feed ingredients. However, this co-product can be used for many other applications due to its valuable chemical composition. Oil is one of the most interesting components of the date seed. In fact, date seeds contain 5–13% oil. Date seed oil contains saturated and unsaturated fatty acids with lauric and oleic as the main ones, respectively. Tocopherols, tocotrienols, phytosterols, and phenolic compounds are also present in significant amounts. These phytochemicals confer added value to date seed oil, which could be used for many applications, such as food product formulations, cosmetics, and pharmaceuticals. This review provides up-to-date data on the different extraction techniques and the chemical composition of date seed oils. The applications of date seed oil have also been reviewed.

The growing interest in natural compounds is helping to improve the management of agro-industrial by-products such as the date seed as sources of such compounds. In this work, the application of a hydrothermal treatment at 160 and 180 °C for 60 min was studied to achieve the solubilization of its phenolic components and sugars in order to obtain biologically active extracts. The percentage of phenols and total sugars in the final extracts were very similar, at 45 and 25% for the 160 and 180 °C treatments, respectively. The treatment at a higher temperature allowed greater solubilization of other components. The antioxidant activity was measured as free-radical scavenging capacity. For the DPPH^• method, expressed as EC50, the results were 0.34 and 0.37 mg/L, the TEAC values for the ABTS^• method were 6.61 and 3.28 mg/g dried extract, and the values obtained by the ORAC method were 12.82 and 9.91 mmol Trolox/g dried extract, for 160 and 180 °C, respectively. All these values are higher than those of other plant extracts and extracts obtained using the whole date. Therefore, the date seed is a very important source of phenols, and through thermal and chromatographic processes, it is possible to obtain extracts with high antioxidant activity.