Martha Zavariz de Miranda

Natural occurrence of deoxynivalenol in wheat from Paraná State, Brazil and estimated daily intake by wheat products.

The occurrence of deoxynivalenol (DON) was evaluated in 113 wheat samples from the northern and central/southwestern regions of Paraná State, Brazil during the 2008 and 2009 growing seasons, and this rate of occurrence was used to estimate the DON dietary exposure. The DON determination was carried out by an indirect competitive enzyme-linked immunosorbent assay. DON was detected in 66.4% samples at levels ranging from 206.3 to 4732.3 μg/kg (mean 1894.9 μg/kg). The estimated daily intake (EDI) of DON through bread and pasta was evaluated in the inhabitants of Londrina City in northern Paraná State, Brazil. The average intake of these inhabitants was 0.79 μg/kg body weight (b.w.) for bread and 0.35 μg/kg b.w. for pasta. The total EDI was 1.13 μg/kg, which is above the Provisional Tolerable Daily Maximum Intake (PTDMI) of 1 μg/kg b.w. To our knowledge, this is the first report on natural DON occurrence in wheat and DON dietary exposure estimation from Paraná, Brazil.

Farinha integral de trigo germinado: 3. Características nutricionais e estabilidade ao armazenamento

O trigo (Triticum aestivum L.) e usado principalmente para alimentacao humana, na forma de farinhas. A germinacao pode ser util para melhorar a qualidade proteica, bem como a de outros nutrientes do trigo, e a estabilidade das farinhas produzidas de trigo germinado e desconhecida. Assim, este trabalho investigou, em laboratorio, o efeito da germinacao sobre algumas caracteristicas nutricionais e sobre a estabilidade ao armazenamento de farinhas integrais de trigo germinado por 48 (FITG48), 72 (FITG72) e 96 horas (FITG96). O perfil de aminoacidos das FITGs foi considerado bom, quando comparado com o da farinha controle e com o do padrao teorico da FAO para pre-escolares (2-5 anos). Somente a lisina (primeiro aminoacido limitante) e a treonina das FITGs mostraram valores mais baixos que o do citado padrao. O escore quimico (em torno de 56-57) e o escore de aminoacidos corrigido pela digestibilidade proteica (em torno de 54-58) foram mais altos nas FITGs que na farinha integral controle (48 e 42, respectivamente). Com base nesses resultados, as caracteristicas nutricionais das FITGs foram melhoradas pela germinacao de trigo. Com relacao a estabilidade ao armazenamento, o pH diminuiu e a acidez alcool-soluvel aumentou de acordo com o tempo de germinacao de trigo. As FITGs foram estaveis ate 4 meses de armazenamento, com excecao da FITG96, que apresentou alto nivel de acidez alcool-soluvel, provavelmente devido a rancidez hidrolitica. O hexanal, uma medida da deterioracao oxidativa, foi encontrado somente na farinha controle; nas FITGs nao foi detectado, indicando boa estabilidade oxidativa durante 6 meses de armazenamento.

Characterization of Brazilian wheat cultivars for specific technological applications

Functional and technological properties of wheat depend on its chemical composition, which together with structural and microscopic characteristics, define flour quality. The aim of the present study was to characterize four Brazilian wheat cultivars (BRS Louro, BRS Timbauva, BRS Guamirim and BRS Pardela) and their respective flours in order to indicate specific technological applications. Kernels were analyzed for test weight, thousand kernel weight, hardness, moisture, and water activity. Flours were analyzed for water activity, color, centesimal composition, total dietary fiber, amylose content and identification of high molecular weight glutenins. The rheological properties of the flours were estimated by farinography, extensography, falling number, rapid visco amylography, and glutomatic and glutork equipment. Baking tests and scanning electron microscopy were also performed. The data were subjected to analysis of variance and principal component analysis. BRS Timbauva and BRS Guamirim presented results that did not allow for specific technological application. On the other hand, BRS Louro presented suitable characteristics for the elaboration of products with low dough strength such as cakes, pies and biscuits, while BRS Pardela seemed suitable for bread and pasta products.

Avaliação tecnológica de biscoitos tipo cookie com variações nos teores de lipídio e de açúcar

A proposta deste trabalho foi investigar o efeito da concentracao de acucar e de lipidio na qualidade tecnologica de biscoitos tipo cookie. Para estudar o efeito das variaveis independentes nas respostas, foi realizado delineamento fatorial 22 (quatro ensaios fatoriais) com tres repeticoes no ponto central, totalizando sete ensaios. Os parâmetros avaliados foram massa e diâmetro antes e apos o forneamento, espessura, fator de expansao, volume especifico e forca de quebra dos biscoitos. Foi observado que, em concentracoes de acucar entre 44 e 57% e em concentracoes de gordura entre 30 e 38%, foram obtidos os maiores diâmetros depois do forneamento e biscoitos com cor amarela mais intensa. Biscoitos com elevadas concentracoes de acucar apresentaram maior fator de expansao e biscoitos com elevadas concentracoes de gordura apresentaram menor forca de quebra.

Aspectos quantitativos e qualitativos do grão de trigo influenciados por nitrogênio e lâminas de água

A field experiment was carried out in a Red-Yellow Latosol in 2009 in order to assess the effects of different doses of nitrogen fertilization and water depth and their interaction on the grain yield and quality of wheat BRS 254. The experimental design was a completely randomized block with split plot on water level and four replications. Nitrogen doses in the plot were: 20, 50, 100, 200, and 400 kg ha-1. In the split plot water depths were: 120, 264, 342 and 392 mm. Mean yield and the majority of its components differed significantly with water depth and nitrogen dose. The exception occurred on the number of grains per spikelet which was not affected by nitrogen level. Minimum and maximum yield were 1,135 kg ha-1 and 5,209 kg ha-1, respectively for 120 mm and 50 kg ha-1 of N; and 392 mm and 200 kg ha-1 of N. In all of them, the highest yields were achieved by nitrogen doses over 220 kg ha-1. Crude protein content was significantly affected by water and nitrogen level interaction. The hectoliter mass, the strength of gluten and the falling number were significantly affected by water level. Water depths lower than 365 mm provided hectoliter weight below 78 kg hL-1. On the other hand water depths higher than 340 mm provided falling number below 250 s, suggesting caution on wheat agrossystems water management.

Efeito do armazenamento à baixa temperatura (-4 ºC) na cor e no teor de acidez da farinha de trigo

During wheat flour storage, biochemical changes can occur which lead to nutritional and technological alterations, but in low temperature these changes can occur more slowly. Among the reactions, we may note are an increase in acidity, reduction of pH and modifications to its color. The present work aimed to evaluate the effects of storage at low temperature (-4 oC) on the color and acidity of wheat flour over six months and to correlate the results obtained to discover whether the acidity has any relationship with the color of the flour. Flours of ten wheat genotypes, cultivated in Cascavel, in Parana State were used. The color was determined via the CIEL*a*b* system using the color parameters: L * (brightness), a* and b * (chromaticity coordinates). The AOAC procedure for lipid acidity was used. The flours displayed a tendency to discoloration during the six-month storage period, with the occurrence of a slight increase in acidity, but with acceptable content. The acidity was not considered to be a factor involved in the alteration of the flour color in the storage at low temperature, because no correlation between these two parameters was observed.

BRS 374 - wheat cultivar

BRS 374 is a wheat cultivar developed by Embrapa. It resulted from a cross between the F1 generation of PF 88618/Coker80.33 and Frontana/Karl. BRS 374 belongs to the soft wheat class, has a low plant height, a high potential grain yield, and white flour.

Optimization of image analysis techniques for quality assessment of whole-wheat breads made with fat replacer

The cellular structure of healthy food products, with added dietary fiber and low in calories, is an important factor that contributes to the assessment of quality, which can be quantified by image analysis of visual texture. This study seeks to compare image analysis techniques (binarization using Dtsu’s method and the default ImageJ algorithm, a variation of the iterative intermeans method) for quantification of differences in the crumb structure of breads made with different percentages of whole-wheat flour and fat replacer, and discuss the behavior of the parameters number of cells, mean cell area, cell density, and circularity using response surface methodology. Comparative analysis of the results achieved with the Dtsu and default ImageJ algorithms showed a significant difference between the studied parameters. The D tsu method demonstrated the crumb structure of the analyzed breads more reliably than the default ImageJ algorithm, and is thus the most suitable in terms of structural representation of the crumb texture.

Propriedades de pasta de mesclas de farinha integral com farinha refinada usadas na produção de pães

In whole wheat bread production in Brazil blends of whole flour (WF) with refined flour (RF) are used, which differ in their composition. Thus, the objective of this study was to investigate the pasting properties of WF with RF blends. Samples with 100% of WF, 100% of RF (controls) and blends of WF with RF in the proportions of 20, 40, 60 and 80% were analyzed, in a RVA (Rapid Visco Analyzer) equipment. The samples pasting temperatures were similar. The peak viscosity decreased proportionally with the increase of WF in blends. Higher values of breakdown and holding strength were found in flour with high viscosity peak. Final viscosity and setback values decreased as the content of WF in blends increased. The pasting properties of WF with RF blends must be seen in a combined way, because they affect bread production and storage. The results also showed that RVA can be used to help in formulating WF/RF blends with certain pasting properties.

Influência do estádio de maturação na colheita e temperatura de secagem de grãos de trigo sobre os valores de energia metabolizável aparente corrigida (EMAc) em frangos de corte

An experiment was performed to evaluate the chemical composition values and Apparent Metabolizable Energy corrected for nitrogen excretion (AMEn) of wheat grain harvested at different maturity stage (13, 16, 20 and 30% of humidity levels) and drying temperatures (40, 70 and 100 oC). The grain with 13% of humidity level was considered dried at harvest and was not submitted to drying. The level of 16% of grain humidity at harvesting and the drying temperature of 40 oC provided the highest AMEn wheat value (3326 kcal/kg, as fed basis). Harvesting humidity and drying temperature affected the nutritional value of wheat. It is necessary to know the best maturity stage at harvest and drying temperatures of wheat grains regarding the variability on its nutritive value and inclusion into poultry diets.