Flaxseed or linseed has been used for food and industrial fiber since ancient times. The terms, "flaxseed" and "linseed" are often used interchangeably, although North Americans use "flaxseed" to describe flax when it is eaten by humans and "linseed" to describe flax when it is used for industrial purposes, such as linoleum flooring. In Europe, the term, "flaxseed" describes the varieties grown for making linen. Flaxseed contains lipid (40%), protein (21%), dietary fiber (28%), ash (4%), and other soluble components such as sugars, phenolic acids, and lignans (ca 6%). The oil content in flaxseed represents between 29 and 45% of the seed depending on the cultivar, location, and agroclimatic conditions. This chapter focuses on the health benefits of flaxseed. The main nutritional advantage of flaxseed oil is related to the high level of ALA in the oil (50%-60%). About 20% of the flaxseed is a mucilagenous hull. Flaxseed mucilage is comprised of gum-like polysaccharides containing acidic (54.5% rhamnose and 23.4% galactose) and neutral arabinoxylan (62.8% xylose). Flaxseed contains about 1%-2% total phenolic compounds, of which the lignan secoisolariciresinol diglucoside (SDG) is a major component. SDG is present in the seed as a mixture of oligomers with hydroxymethylglutaric acid having an average molecular weight of 4000 Da.
Fitzpatrick, K. C. (2011). Health Benefits of Flaxseed. In Omega-3 Oils: Applications in Functional Foods (pp. 213–264). Elsevier Inc. https://doi.org/10.1016/B978-1-893997-82-0.50013-X