The powder obtained was identified as date palm seed powder (DPSP). The composition (w/w) of the DPSP has been reported in our previous paper as protein, 5.64%, moisture, 5.39%, fat 8.14%, fibre 18.50%, ash 0.95%, carbohydrate 61.38%
Oil was extracted from DPSP using a Soxhlet apparatus. Fifteen gram samples of dried DPSP were weighed into an extraction thimble
and sealed with cotton wool. The thimble was inserted in a Soxhlet extraction flask and extracted with boiling hexane (boiling point 68 °C) for 10 h or until the solvent at the sample chamber was colourless,
indicating it was free from oil and that all the oil had been extracted. The defatted DPSP was removed from the extraction thimble and left to dry overnight, to allow the hexane to evaporate.
This defatted date seed powder (DDSP) was kept at −20 °C until processed further.
The residual fat content and protein content of the defatted powder were reported previously as 1.01% (w/w) and 6.13% (w/w), respectively.