Conclusion

The flax antioxidant system appears to be a water-soluble system.  Hull had no effect on the antioxidant properties of the meal, suggesting that SDG, mainly present in the hull, was not involved in the flax antioxidant system.

Flaxseed contained no free phenolic acids.  After alkaline hydrolysis of an ethanol extract, SDG ferulic and p-coumaric acid glycosides were found.  Water extracts of flax meals showed some antioxidant properties but their effect was minimal compared to the antioxidant properties of the non-extracted meal.  This suggested that the main flaxseed antioxidant system is water-soluble.  Flax phenolic compounds were found to have some antioxidant properties but they are not the main flaxseed antioxidant system.