Further compositional analyses of flax: Mucilage, trypsin inhibitors and hydrocyanic acid

Abstract

Registered Canadian cultivars of flax, and laboratoryprepared and eommereially obtained samples of linseed meal (LM), were used to determine extract viscosity and mucilage, trypsin inhibitors and hydrocyanic acid (HCN) concentrations. The mucilage readily leached out from the seed coat (hull) fragments soaked in water, leaving behind pentagon-shaped cells that could be seen clearly in scanning electron micrographs. Extract viscosity significantly varied in the laboratory-prepared (23-48 cS) and commercially obtained (30-68 cS) samples of LM and may be used to obtain an indirect, qualitative estimate of flax mucilage. Mucilage was extracted from whole seed in 5.0-5.3% yields and contained 20-24% protein (about 10% ash and 30% total carbohydrates). Laboratory-prepared LM (raw) contained 42-51 units of trypsin inhibitor activity, commercially obtained samples, 14-37 units, and raw rapeseed and soybean meals, 99 and 1650 units, respectively. Picric acid tests (qualitative) showed only traces of HCN in ten cultivars of freshly ground flax. The acid silver nitrate titration procedure measured HCN quantitatively, but showed its presence only in three of the five cultivars investigated. HCN was conveniently measured by a colorimetric procedure (barbituric acidpyridine reaction), which may be used to screen flax cultivars. HCN content of flax was significantly influenced by environments (growth location and season) and, to a less extent, by cultivar.

Performance and carcass characteristics of growing-finishing pigs fed barley-based diets supplemented with Linpro (extruded whole flaxseed and peas) or soybean meal

“…This decrease in growth could be due to the presence of anti-nutritional factors in flaxseed such as mucilage (Bhatty 1993), cyanogenic glycosides (Conn 1969), allergens (Spies 1974) and vitamin B 6 antagonists (Klosterman 1974 For personal use only.…”

Effect of dietary flaxseed on broiler growth, erythrocyte deformability, and fatty acid composition of erythrocyte membranes

“…A reduction in growth of birds under hypobaric pressure has also been previously reported (Mirsalimi et al 1993;Bond et al 1996). The decrease in growth with diets containing flaxseed may be due to the presence of antinutritional factors such as mucilage (Bhatty 1993) cyanogenic glycosides (Conn 1969), allergens (Spies 1974) and vitamin B-6 antagonists (Klosterman 1974). However, in formulating the diets, soybean protein was substituted by flax protein and thus changes in the protein component of the diet may also be important.…”

Flaxseed—a potential functional food source

“…While in humans, flaxseeds are not found to be associated with vitamin B6 deficiency (Dieken 1992;Ratnayake et al 1992). Trypsin inhibitors are also reported in flaxseed, though activity is insignificant as compared to soybean and canola seeds (Bhatty 1993).…”