Characterization of chia seed oils obtained by pressing and solvent extraction

Abstract

The oil yield, fatty acid composition and the physicochemical and quality characteristics of chia crude seed oils obtained by pressing and solvent extraction were determined. The extraction methods assayed influenced significantly the oil yield, obtaining about 30% more oil by solvent than by pressing. The main fatty acids ranked in the following order of abundance: α-linolenic acid (α Ln). > linoleic acid (L). > oleic acid (O). ≈ palmitic acid (P). > stearic acid (S) for both extraction systems. The n-3/. n-6 FA ratio of chia oils ranged from 3.18 to 4.18, being markedly higher than that reported for other vegetable oils. The main triacylglycerols were: αLnαLnαLn. > αLnαLnL. > αLnLL. > αLnαLnP. > αLnLO. ∼ αLnLP, which represent about 87-95% of the total content of these compounds. The quality and composition of some minor constituents of chia seed oils were influenced by the extraction process. Oils presented a moderate content of bioactive components, such as tocopherols, polyphenols, carotenoids and phospholipids; the high unsaturation level determined their low oxidative stability.