Simultaneous extraction of oil and antinutritional compounds from flaxseed

Abstract

AbstractA two‐phase solvent extraction process, developed in our laboratory for rapeseed, was used to simultaneously extract oil and toxic, antinutritional components from flaxseed to produce a meal suitable for animal feed. The most effective solvent systems consisted of hexane in combination with a solution of methanol that contained 10% (vol/vol) water and 2.5–5% (w/w) ammonia, or methanol that contained 10% water (vol/vol) and 0.08% (w/w) NaOH. The treatments were carried out both at laboratory and semipilot‐plant scales. The success of the test with a pilot‐scale Karr liquid‐liquid extraction column suggested that this process could be readily carried out on an industrial scale. The resulting flax meal had a high protein content (40–47%) and low levels of cyanogenic glycosides (reduced by 90–100% from the starting material). The methanol‐ammonia extraction reduced the total polyphenol content by ≈20%. The oil extraction efficiency of the Karr column was high, resulting in meal residual oil contents of ≈1%.