Purpose – Flaxseed (FL) is a nutrient rich seed but contains cyanogenic glycosides, which can release hydrogen cyanide (HCN) into the body after consumption. This study aims to determine the cyanogenic content of raw and heated (170°C, 15 min) flaxseed as well as its effect on the blood thiocyanate (SCN−) concentration, a derivate of HCN, in rats. Changes in liver and kidney enzymes level of blood are further studied.

Design/methodology/approach – Rats were assigned into groups of control, 10 percent, 20 percent and 30 percent of either raw or heated FL, in basal diet, for duration of 30 days. Cyanogenic content of FL analyzed using picrate method and blood thiocyanate concentration analyzed using high performance liquid chromatography.

Findings – Raw ground flaxseed had 251.14±9.11 mg HCN/kg food, which significantly reduced by 8.5 percent after heating. Generally heated FL groups showed lower (but not significant) blood thiocyanate compared to raw FL groups. Blood SCN elevated by increasing the dosage of flaxseed. However, only in 30 percent raw FL group the difference was significant (p<0.05). Liver and kidney enzymes were not changed significantly in all groups (p>0.05). This study suggests that consumption of flaxseed in high dosage (20 percent to 30 percent) is better to be in heated form to result in lower blood thiocyanate concentration.

Originality/value – This study may provide better understanding for safer usage of flaxseed in animals and even human interventional studies and may be applicable to flaxseed consuming food industries.