Experimental study and optimization of the extraction of Algerian date stones oil (Phoenix dactylifera L.) using supercritical carbon dioxide

An experimental extraction of Algerian date stones oil was carried out using supercritical carbon dioxide. Response surface methodology was used to investigate the effect of pressure (150-250 bar), temperature (313-333 K) and particles diameter (0.3-0.9 mm) on the extraction yield. The comparison of the predicted results with the experimental values confirmed the reliability of this technique. The optimum yield value was determined around 14.26% and was obtained at a pressure of 250 bar, a temperature of 333 K and particles diameter of 0.3 mm. the conventional solvent extraction using Soxhlet apparatus shows that the oil content of the date stones sample was about 16.22%. The fatty acids composition was determined using GC-FID analysis, showing that the oleic acid was the major compound present in this oil. Practical applications Locally date stones are an abundant waste product of date processing industries which are rich in many valuables substances such as carbohydrates, oil, dietary fibers, vitamins, proteins, bioactive polyphenols and natural antioxidants, making them an attractive source for the extraction of bioactive compounds because of their low cost and high nutrient content. They can be used in many applications like the production of caffeine-free coffee, food products formulation, cosmetics, and functional and medicinal supplements. They are a by-product that can be easily collected and recycled in an economic and sustainable way. Also date stones oil is a great source of saturated, monounsaturated and polyunsaturated fatty acid acids which have several good human health benefits. The use of supercritical carbon dioxide extraction of date stones oil can be regarded as a great opportunity to develop the production of high quality date stones oil and exploit all the mentioned important properties.