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Oils extracted from the seeds of two date palm (Phoenix dactylifera L.) cultivars, Deglet Nour and Allig, collected from Tunisia, were compared in terms of phenolic, tocopherol and sterol profiles. These minor components are not only very important for functional properties of oils (oxidation resistance, taste, aroma and color), but could also have many health benefits. Total phenols, considered as the principal source of oil oxidation resistance, ranged from 520.81 for Deglet Nour to 220.32 mg/kg for Allig. High performance liquid chromatography revealed eight identified peaks for which the major component was hydroxytyrosol (10.21%) for Deglet Nour and tyrosol for Allig (8.10%). Total sterol content was 3500 and 3000 mg/kg for Deglet Nour and Allig, respectively. The sterol marker, β‐sitosterol, accounted for 83.31 and 78.66% of total sterols in Deglet Nour and Allig seed oils, respectively. Alpha‐tocopherol was the predominant component in both date seed oils (24.97–38.85%).

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In this study, olive leaves, which are known for their therapeutic and antioxidant properties, were used to assess the effect of solar drying conditions (temperature and flow rate) on the drying time and quality parameters of olive leaves. Samples were dried at three drying temperatures (40, 50 and 60°C) and at two drying air flow rates (1.62 and 3.3 m 3 min )1 ) in a convective laboratory solar dryer. From the experimental results, it was noted that the drying time required to reduce the moisture content to 0.10 kg kg )1 d.b. depends mainly on the drying temperature. The quality attributes of the dehydrated olive leaf samples were investigated in term of colour, total phenols and radical scavenging activity. The effect of solar drying on L*, a* b* parameters was significant (P < 0.05) for all the studied olive leaves. Besides, the total phenols of olive leaves were significantly (P < 0.05) influenced by drying air conditions and tended to decrease with increased drying time. The DPPH radical scavenging activity was higher in fresh [EC 50 39.40 (ZR)-39.95 (CH)] than in dried leaves. However, the radical scavenging activity was also high in leaves dried at 60°C, 3.3 m 3 min )1 [EC 50 54.21 (ZR)-68.79 (CL)].

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