Abstract
Two years experiment was carried out to compare the nutritional composition in bulbs of ten onion cultivars grown in the field conditions. Pyruvic acid, ascorbic acid and soluble sugars were determined in the edible part of onion bulbs. In most cultivars the content of pyruvate as the pungency index was ranged between 3-7 μmol g-1 fresh weight (medium pungency), however, three of them exceeded 7 μmol g-1 fresh weight (high pungency). A higher level of pyruvate corresponded in most cases with higher sugar content but was not correlated with that of ascorbic acid.