Veterinary session

Cyanogenic glycoside contents of certain cultivars of flaxseed (Linum usitatissimum) were examined in course of our study. Cyanogen glycosides are nitrogen-containing secondary metabolites that are quite common in plants and whose main function is to protect against certain pathogens during the plant life.

They do not have a direct biological effect in the glycosidic form, however entering into the animal or human body, the highly toxic HCN will be released enzymatically. Our goal was to determine the amount of HCN released from the flax seeds (or from seedlings) of some cultivars, as well as to monitor their changes during the germination.

In our study, we compared two domestically breed ‘Helga’ and ‘Zoltán’ flax cultivars, which are also important from a feeding point of view, and ‘Golden Bio’ cultivar from the organic shop, intended for human consumption. The test method was a picric acid test. Detection is based on the colour reaction of alkaline picric acid paper. Picric acid reacts with HCN released from the plant in the closed space of the reaction vessel, resulting the red Na isopurpurate. The colour of picric acid test papers was evaluated qualitatively and the amount of dye dissolved from the paper was measured spectrophotometrically at a wavelength of 483 nm. The seeds of the cultivars were germinated in the dark, at which we found a higher rate of germination. Sampling was performed on days 0 (dry seeds), 1, 3, and 7th days, respectively.

We found important to examine the difference between germination phases as there is emphasis not only on selection work but on the adequate storage of fodder which is just as important as the selected fodder, this was supported by our measurements as well.

Our results allowed us to draw several conclusions. The cyanogenic glycoside content in seeds of studied cultivars was on day 0 between 14.51 - 42.63 mg/kg. Among the studied cultivars, ‘Golden Bio’ flaxseed (42.63 mg/kg) showed cyanide release above the hazard level (20 mg/kg) even in the dry state. Feeding of ‘Helga’ and ‘Zoltán’ cultivars as dry seeds is still allowed, they have produced low HCN values compared to the data of literature.

However, during germination, the initial stage of which is characterized by a very significant and well-known water uptake, the level of cyanogenic glycosides (or cyanide) increased significantly and dynamically. On day 7, it reached a multiple of day 0 and a concentration between 1264.35 - 1385.31 mg/kg was measurable. Thus, it is also possible to release HCN molecules from cyanogenic glycosides, which can have serious toxicological consequences for both animals and humans.

Our work raises further questions about the cyanide carrier role of flax seeds (flax seed products) and its prevention. We evaluate that a simple picric acid test can prevent and prevent HCN poisoning where appropriate and at the site. Our view is that HCN poisoning can be prevented by performing of a simple picric acid test.