Proximate composition of polyphenolic, phytochemical, antioxidant activity content and lipid profiles of date palm seeds oils (Phoenix dactylifera L.)

Abstract

Palm date seeds oil of eight varieties were investigated for physical, chemical, and phytochemical analysis, and compared to used commercial oils. Significant differences were observed among varieties. The oil content of the eight varieties ranged from 6.05 to 10.25%. Fatty acid analysis using GC-MS revealed that oleic acids were the dominant component (38.67–44.38%) followed by lauric (21.72–26.66%), myristic (11.26–13.04%); palmitic (9.65–11.38%); linoleic (6.25–8.24%); stearic (3.06–3.32%) while linolenic acid was found in traces. The carotenoids content ranged from 17.57 ± 0.02 to 12.35 ± 0.03 mg/kg oil, total phenolic content ranged from 58.04 ± 0.30 to 181.03 ± 0.75 mg GAE/100 g and flavonoids content values ranged from 22.81 ± 0.08 to 53.41 ± 0.72 mg RE/100 g oil. The antioxidant activities (DPPH and ABTS) varied from 17.28 ± 1.06 to 47.37 ± 1.05 and 3.10 ± 0.28 to 8.83 ± 0.08 mg AAE/100 g, respectively. The phenolic compounds identified in seed oils were hydroxytyrosol (30.36 ± 0.21 to 38.63 ± 0.14 μg/g oil), procatechuic acid (14.47 ± 0.09 to 35.21 ± 0.07 μg/g oil), tyrosol (14.36 ± 0.03 to 21.23 ± 0.12 μg/g oil), gallic acid (7.37 ± 0.04 to 17.68 ± 0.09 μg/g oil), caffeic acid (3.21 ± 0.11 to 7.09 ± 0.12 μg/g oil) and oleuropein (1.37 ± 0.02 to 7.27 ± 0.05 μg/g oil). The total amount of the identified phenolic compounds recorded in Bouslikhan variety (107.32 μg/g oil). The results suggest that palm date seeds oil are strong radical scavengers and can be considered a good source of natural antioxidants for medicinal, functional food, and commercial uses. • Palm date seeds yield an important oil content up to 10%. • The seeds oils are rich in lipid content and the major fat is linoleic and oleic acid. • The major phenolic compounds in the palm date seeds oils were hydroxytyrosol and Protocatechic acid. • The date seeds oils showed remarkable antioxidant activity. • Polyphenolics alongside fatty acids profile showed remarkable phenotypic effect.