Centesimal composition and vitamin C, calcium and phosphorus contents in six lettuce cultivars produced under two cultivation systems

Abstract

The objective of this work was to analyse the effect of two cultivation methods (convencional-soil and hydroponic) concerning the centesimal composition and levels of vitamin C, calcium, phosphorus in six lettuce cultivars (Aurora, Lívia, Brisa, Mimosa, Regina and Verônica). The lettuce grown in hydroponic method presented increases of 1,33%; 33,6% and 168,7% in water, protein and phosphorus than the convencional method and a reduction of 23,3%; 27,8%; 18,6%; 44,6%; 46,6% and 18,2% in dry weight matter, ethereal extract, calcium, fibre, total carbohydrates and caloric value. Inferior level of mineral residue was observed in cultivars Lívia and Mimosa grown in the conventional method. On the other hand, the cultivar Brisa grown hydroponically presented higher content of mineral residue. The convencional method provided the smaller content of total carbohydrates in all cultivars studied. Therefore, the hydroponic lettuce does not lose in nutricional quality for the lettuce grown in soil and its principal advantage is the minor caloric value.