The use of hempseed flours in the animal diets may be limited by the presence of antinutritive compounds. The content of phytic acid, condensed tannins, trypsin inhibitors, cyanogenic glycosides and saponins was evaluated in hempseed meal of three italian varieties (dioecious) and three french varieties (monoecious) of Cannabis sativa L. The analysis of variance showed significant differences among varieties for all the antinutritional compounds. The italian and french hemp groups resulted significantly different in the content of phytic acid, trypsin inhibitors and cyanogenic glycosides. The concentration of phytic acid in the hempseed flour deserves attention in both groups, while the content of cyanogenic glycosides deserves attention just in the french varieties, and condensed tannins, trypsin inhibitors and saponins are instead to acceptable levels. The french varieties presented less phytic acid than those italians (-0.55 g Kg -1 of dry matter).
The content of phytic acid in hemp varieties resulted inversely correlated with trypsin inhibitors and cyanogenic glycosides. Since the presence of phytic acid in meal may lead to mineral deficiencies over a long period of administration, the phytic acid contents in hempseed flour should be reduced to increase the safety of these flours, but avoiding altering trypsin inhibitor and cyanogenic glycoside contents.”