Unexploited Acacia cyanophylla seeds: potential food sources of ω6 fatty acids and antioxidants?

BACKGROUND: In order to investigate new sources of dietary phytochemicals, recent studies have focused on underexploited seeds. In this study the total lipid contents, fatty acid profiles and levels of soluble proteins, minerals and antioxidants in seeds from 12 Acacia cyanophylla ecotypes commonly grown in Tunisia were determined. RESULTS: Total lipids averaged 101.7 g kg(-1) on a dry weight basis. Linoleic (61.11-65.45% of total fatty acid content), oleic (19.67-22.85%) and palmitic (9.18-9.98%) acids were the principal fatty acids. Smaller proportions of stearic (1.49(-1).82%), vaccenic (1.13-2.05%) and palmitoleic (0.34-0.58%) acids were also quantified. Proteins (by Kjeldahl assay) averaged 107.2 g kg(-1) on a dry weight basis. Total phenolics averaged 1.91 g gallic acid equivalent kg(-1) dry weight (DW) and total flavonoids averaged 0.40 g rutin equivalent kg(-1) DW. The free radical-scavenging activity determined by 2,2-diphenyl1- picrylhydrazyl assay averaged 0.59 mmol L-1 Trolox equivalent antioxidant capacity (TEAC), while that determined by 2,2 beta-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay averaged 0.28 mmol L-1 TEAC. CONCLUSION: The findings of this study confirm the presence of.6 fatty acids at high levels in A. cyanophylla seeds. These metabolites could be used as such and/ or extracted for the formulation of supplements and/ or ingredients to provide a ratio close to the ideal for the omega 3/omega 6 balance. (C) 2012 Society of Chemical Industry