Chemical characterization and antioxidant potential of Chilean chia seeds and oil (Salvia hispanica L.)

- Analysis of Chilean chia seeds and oil (Salvia hispanica L.).
- The chia seeds presented a good nutritional source of protein, oil and total dietary fiber.
- Chia oil contains mainly α-linolenic acid, with a low n-6/n-3 fatty acid ratio.
- Important phenolic compounds were identified in chia seed and oil.
- The samples exhibited a high antioxidant activity in all in vitro methods evaluated.

The objective of this study was to chemically and nutritionally characterize the commercial chia seeds and oil from Chile and investigate their antioxidant potential by different in vitro methods. The chia seed presented a good source of protein (25.32 g/100 g), oil (30.22 g/100 g) and total dietary fiber (37.50 g/100 g), with predominant insoluble fiber (35.07 g/100 g). The main fatty acids, ranked order of abundance, were α-linolenic acid > linoleic acid > palmitic acid ∼ oleic acid > stearic acid. The triacylglycerols (TAG) in chia oil were identified by direct mass spectrometry using the easy ambient sonic-spray ionization (EASI-MS) technique and linolenic acid (Ln) was present in the most TAG found. The oil also presented a low peroxide index value (2.56 mEq peroxide/kg). The samples exhibited a high antioxidant activity by the various in vitro methods evaluated; it is due to the presence of phenolic compounds in the seed or oil, which were, mainly, myricetin, quercetin, kaempferol, chlorogenic acid and 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4-DHPEA-EDA). Our results therefore suggest that Chilean chia seeds and oil should be considered as functional ingredients with high antioxidant potential in food products with commercial applications.