Qualidade de fritura de tubérculos de batata produzidos sob cinco doses de nitrogênio

Abstract

Nowadays, potato is the most important vegetable in Brazil and frying is the preferable way to consume it. Potato processing industry requires tubers characteristics as: uniform size and color, besides chip golden color. The main factors to achieve these characteristics are: high dry matter and low content of reducing sugars. Tuber quality is influenced by genetics and environmental factors such as storage temperature. The objective of this work was to evaluate chip processing quality produced with five doses of nitrogen. Tubers of cultivar Asterix were planted on september the 2nd in 2003 at UFSM. The treatments consisted of five N concentrations in the nutrient solution, expressed in mmol.L-1: 5.0(T1), 8.3(T2), 11.3(T3), 14.3(T4) and 16.3(T5). Tubers were harvested on december the 17th in 2003, 104 days after planting. Tubers cured for 15 days at 20ºC and immediately after curing, tubers were organized in four replicates of nine tubers and determined dry matter, reducing sugars and chip color. Potatoes were stored in chambers at 4ºC, 10ºC and 20ºC for 30 and 60 days and revalued for dry matter, reducing sugars and chip color. Nitrogen doses applied during potato growth alter chip quality. Dry matter content was affected by N doses, but these values reduced with doses higher than 11,3mmolN.L-1. The results show that only tubers from T2 and T3 achieved the minimum content of dry matter suggested by literature which is 20g.100g-1.It was not observed a relationship between reducing sugars and chip color with nitrogen doses before storage time. After the storage at 4ºC, dry matter showed a little variation with N doses after 30 days of storage, while after 60 days it was observed a reduction of this characteristic. At 10 and 20ºC the regression curves showed less content of dry matter according to higher doses of nitrogen. Nitrogen doses did not affect chips color, independently of temperature and storage time, however dry matter was affected by nitrogen doses, temperature and storage time. Other factors besides nitrogen influence chip color and reducing sugars at potato tubers cv. Asterix.