Oil is one of the major components of date seed alongside dietary fibre, carbohydrate, protein, moisture and ash. Therefore, the present work focused on the extraction of oil from five varieties of date seed using Soxhlet extraction method and subsequently characterised their physicochemical and antioxidant properties accordingly. Oil extracted from the seeds ranged between 8 to 9.8%, whereas the iodine values were between 48.7 to 55.5 g I2/100g. Furthermore, oleic and lauric acids were revealed as the main fatty acids present in the date seed oil, with LaOO (La: lauric acid; O: oleic acid) as the main triacylglycerol. The total phenolic content in the oil ranged from 7.96 to 17.72 mg GAE/g oil, while the antioxidant activity, expressed as EC50, ranged from 5.17 to 17.18 mg/mL. Additionally, the highest reducing activity was observed at 4mg/mL. Hence, oil characteristics are dependent on the type of date, thus indicating that different potential applications may be suggested.
Full-fat roasted date seeds are considered an excellent source of antioxidants which can treat many diseases. The specific objectives were to investigate the effect of roasting temperature and time on the hardness of whole seeds, moisture content of the roasted date seeds powder, DPPH radical scavenging activity, total phenolic contents, extraction yield, pH, browning index and sensory properties of the brew prepared from the full-fat roasted date seeds and to construct descriptive models that could describe this effect. Date seeds were roasted at three temperatures (160, 180 and 200 °C) for different period of times (10, 20 and 30 min) using a natural conventional oven; then grinded and next brewed. Hardness of whole seeds, moisture content of the seeds powder, DPPH radical scavenging activity and total phenolic contents, extraction yield, pH and browning index and sensory properties of the brew were significantly affected by the roasting conditions. The statistical results indicated that the proposed model could adequately describe the measured properties. Strong correlations have been found among the properties of the brew as well. The producers of the date seeds brew can utilize these results for controlling the roasting process.