Flax seed meal, the by-product of producing linseed oil from flax seeds, is used as livestock fodder. Flax seeds occur in two basic varieties/colors: brown or yellow (golden linseeds). Most types of these basic varieties have similar nutritional characteristics and equal numbers of short-chain omega-3 fatty acids.
Yellow flax seeds, called solin (trade name "Linola"), have a similar oil profile to brown flax seeds and both are very high in omega-3s (alpha-linolenic acid (ALA), specifically). Flax seeds produce a vegetable oil known as flax seed oil or linseed oil, which is one of the oldest commercial oils. It is an edible oil obtained by expeller pressing and sometimes followed by solvent extraction.
Linseed oil, also known as flaxseed oil or flax oil (in its edible form), is a colourless to yellowish oil obtained from the dried, ripened seeds of the flax plant (Linum usitatissimum). The oil is obtained by pressing, sometimes followed by solvent extraction. Linseed oil is a drying oil, meaning it can polymerize into a solid form. Owing to its polymer-forming properties, linseed oil can be used on its own or blended with combinations of other oils, resins or solvents as an impregnator, drying oil finish or varnish in wood finishing, as a pigment binder in oil paints, as a plasticizer and hardener in putty, and in the manufacture of linoleum. Linseed oil use has declined over the past several decades with increased availability of synthetic alkyd resins—which function similarly but resist yellowing.
Flaxseed oil is an edible oil in demand as a dietary supplement, as a source of α-Linolenic acid, (an omega-3 fatty acid). In parts of Europe, it is traditionally eaten with potatoes and quark. It is regarded as a delicacy due to its hearty taste and ability to improve the bland flavour of quark.
Flaxseed oil is a triglyceride, like other fats. Linseed oil is distinctive for its unusually large amount of α-linolenic acid, which has a distinctive reaction with oxygen in air. Specifically, the fatty acids in a typical linseed oil are of the following types:
The triply unsaturated α-linolenic acid (51.9–55.2%),
The saturated acids palmitic acid (about 7%) and stearic acid (3.4–4.6%),
The monounsaturated oleic acid (18.5–22.6%),
The doubly unsaturated linoleic acid (14.2–17%).