Adubação nitrogenada e sulfurada na qualidade tecnológica do trigo

• Ano de defesa: 2010
• Autor(a) principal: Oliveira, Ludmilla de Carvalho
• Orientador(a): Pirozi, Mônica Ribeiro
• Banca de defesa: Fontes, Edimar Aparecida Filomeno , Cruz, Renato Souza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Trigo; Adubação; Qualidade de panificação
• Palavras-chave em Inglês: Wheat; Fertilization; Breadmaking quality
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/2883

The breadmaking quality of wheat is strongly determined by the quantity and composition of the glutenin proteins, in particular, glutenin subunits (HMW - High Molecular Weight and LMW - Low Molecular Weight), wich provide the unique viscoelastic properties needed to impart adequate volume and texture in bread doughs. The soil availability of sulfur (S) and nitrogen (N) may affect both the amount and composition of protein in the wheat grain, so that the induction to a optimal N/S ratio by fertilization can improve the characteristics of grain, flour and bread. The overall aim of this work was to study the effect of sulfur and nitrogen fertilization, through the supply of N as ammonium sulfate and urea at doses of 35, 70 and 105 kg N / ha, on the gluten protein composition and technological characteristics of wheat cultivars UFVT 1-Pioneiro and EMBRAPA 22, in two seasons. The high molecular weight glutenin subunits (HMW-GS) were identified using SDS- polyacrylamide gel electrophoresis (SDS-PAGE) and protein fractions and weight distribution determined by size exclusion high performance liquid cromatography (SE-HPLC). The results of SDS-PAGE and SE-HPLC were compared to the bread score, bread volume and specific volume in the bakery tests. It was identified the subunits 1, 7+8 e 5+10 for EMBRAPA 22 and 1, 17+18 e 5+10 for UFVT 1-Pioneiro. In the first season, the protein content was higher with the application of ammonium sulfate, percent of polymeric protein total (PPP) with urea, while percent of polymeric protein unextractable (UPP) did not change. The best overall bread score, volume and specific volume were observed with wheat flour treated with 105 kg N / ha. The characteristics of the breads were not related to the protein, nor with the protein polymer fractions. In the second season, higher amounts of protein, percent of polymeric protein on flour (PPPF), percent of polymeric protein unexctrable (UPP) and percent of polymeric protein unextractable on flour (UPPF) were associated with EMBRAPA 22 and the highest N rate, regardless of source of fertilizer used. Breads with the best scores were obtained with wheat cultivar UFVT 1-Pioneiro treated with urea and wheat flour that received the lowest N rate. Higher volume and specific volume were related to cultivar UFVT 1-Pioneiro under fertilization with ammonium sulfate. The baking test results did not relate to the values of PPP, PPPF, UPP and UPPF and protein content. In adition the bread score was not related to volume and specific volume.