Changes in free, esterified and glycosidic phenolic acids in cereal grains during the after-ripening

Experiments were conducted on rye (Secale cereale L., cv, Dankowskie Zlote) triticale (Triticosecale, cv. Dagro), barley (Hordeum vulgare L., cv. Ars) and oat (Avena sativa L., cv. Boruta) caryopses. Caryopses from each species were collected in full ripeness and divided into two batches. From one batch phenolic acids were isolated and fractionated immediately after harvesting, and from the other part the same was done after six months storage in dry state. Dormant caryopses slowly lost their dormancy by the process of after-ripening, and after six months storage in dry state (in all investigated species) caryopses were completely released from dormancy. During after-ripening quantity and quality changes were found both among free and soluble bound phenolic acids. In all examined species, the decreased level of free and conjugated forms (esters and glycosides) was found during several months storage in dry state. This indicates a positive correlation be tween dormancy levels and the contents of phenolic acids in the process of after-ripening, supporting the idea of involvement of phenolic compounds in the control of dormancy and sprouting in cereal caryopses.