Quality of Tomato Ferti Lized with Nitrogen Essay
The influence of different levels of nitrogen (N1, N2), phosphorous (P1, P2) and N+P (N1P1, N1P2, N2P1, N2P2) mixed fertilizers was investigated on volatile substances, soluble sugars, organic acids, titratable acidity, dry matter and lycopene of “Corbarino” cherry-like tomatoes. The flavor volatiles reached the highest concentrations in red-ripe cherry-like tomatoes treated with N1. Glucose, fructose, dry matter and titratable acidity increased only in N+P fertilized samples. Among the organic acids, citric increased, malic decreased and oxalic was constant in all the fertilized samples. Lycopene reached the highest values in N2 and N2P2 samples.
INTRODUCTION …show more content…
Soluble sugars and organic acids play an important role in the characterization of the tomato taste. Sugars (glucose, fructose and traces of sucrose) and organic acids (citric, malic and oxalic) represent half of the total dry matter of tomato fruit (SILVESTRI and SIVIERO, 1991).
In tomato cultivation, fertilizer application regimes can play an important role both to increase the yield and size and to improve the nutritional and nutraceutical quality of the fruit. A large amount of N is required for optimum production as the tomato root absorbs a great deal from the soil. N-deficiency can cause a decrease in production (number and size of tomatoes), a reduction in storage quality, colour, and tomato taste (SAINJU et al., 2003).
Secondary plant metabolites which lack N in their structure such as lycopene, β-carotene, phenolics and flavonols are favoured under Nlimiting conditions, although photosynthetic activity is not simultaneously reduced. However nitrogen-containing compounds are