Lucerne tannins. II. Isolation of tannins from lucerne, their nature and influence on the digestive enzymes in vitro

Tannic substances were isolated from dehydrated lucerne meal and it was found that they contained free gallic acid, gallotannins and flavanols. In the procedure for their isolation, cation and anion exchange resins, Amberlite IR‐120 and Amberlite IR‐45, were used. The isolated tannin was tested as an inhibitor of tryptic digestion of casein, L‐amylolytic digestion of starch and lipase enzymes. In in vitro studies it was found that the isolated tannin has a high inhibitory action on digestive enzymes.