Luiz Carlos Gutkoski

Effect of single and dual heat-moisture treatments on properties of rice, cassava, and pinhao starches.

The effects of single and dual heat-moisture treatment (HMT) of rice, cassava and pinhão starches at 100 °C and 120 °C were investigated. The starches were adjusted to 22% w.b. moisture content and subjected to single HMT (autoclaved for 2 h) or dual HMT (after being autoclaved for 1 h, the material was allowed to stand for 24 h and was autoclaved again for more 1 h). Starch crystallinity, solubility, swelling power, thermal properties, pasting properties, and gel hardness were evaluated. The temperature variation affected more the starch properties than the single or dual HMT. The starch subjected to single HMT at 120 °C was the most applicable to food applications, where low swelling power, low viscosity and high thermal stability are necessary.

Desenvolvimento de barras de cereais à base de aveia com alto teor de fibra alimentar

Cereal bars are a nutritional food of sweetened and acceptable flavor and are a source of vitamins, minerals, fibers, proteins and complex carbohydrates. The objective of this work was to study the effect of dietary fiber concentration and sugar in cereal bars made of oats with a high dietary fiber content. In the research, oat flakes, bran and flour from cultivar UPFA 22, selected on the basis of the dietary fiber and b-glucans content, were used. The ingredients were used in amounts defined in laboratory tests. The experiment was carried out using a central composite rotational design applicable to the response surface methodology (RSM), and the effects of the sugar syrup concentration (70, 75 and 80 °Brix) and dietary fiber content in the formulation (12, 16 and 20%) on the chemical composition, calorie value, water activity, microbiology and sensorial characteristics of the cereal bars were evaluated. The results were analyzed by multiple regression and the significant linear, quadratic and interaction terms were used in the second order mathematical model. The results showed that oats can be used as an ingredient when making cereals bars presenting an adequate texture, flavor and appearance. The oats used in the formulation makes cereal bars with high dietary fiber and b-glucan content. The bars present acceptable sensorial properties, similar to the industrialized bars, with higher acceptability when made with average concentration of sugar and high dietary fiber content. The cereal bars present low water activity and are within sanitary specifications and can be stored for 60 days.

Procedimento para teste laboratorial de panificação: pão tipo forma

Among the available determination to evaluate objectively the proprieties of the mass aiming to predict the use of the flour for the some products of bread making, mixture features, extension features, viscosity and production or gas clamping are included. The present work had as the objective to evaluate the quality of wheat flour using the laboratorial test of bread making for form bread type. Samples of grain and wheat flours were evaluated as for the physical, chemical, rheologycal features and functionaries. The results allow to conclude that the laboratorial test of bread making used present repeatability and can be executed in the laboratory to evaluate the features of bread making of flours. The total time for the accomplishment of the test is 128 minutes, being 13 minutes of mixture, 10 minutes of mass rest, 90 minutes of fermentation and 15 minutes of baking in the temperature of 220°C.

Avaliação de farinhas de trigos cultivados no Rio Grande do Sul na produção de biscoitos

Na industria de biscoitos e fundamental a definicao de parâmetros para selecionar o uso do trigo em estudo. Existe uma serie de testes quimicos, fisicos, enzimaticos e funcionais que podem caracterizar a qualidade tecnologica da farinha. Com o presente trabalho objetivou-se estudar diferentes cultivares de trigo cultivados no estado do Rio Grande do Sul para a producao de biscoitos tipo semi-duros atraves de analises fisicas, quimicas, reologicas e funcionais. Graos de trigo de amostras dos cultivares BR 23, BRS 120, BRS 49, BRS 177, BRS 119, BRS 176, PF 940097 e Embrapa 40 foram condicionados para 15% de umidade, moidos em moinho piloto Chopin e analisados. As determinacoes realizadas foram peso de mil graos, dureza do grao, peso do hectolitro, moagem experimental, composicao quimica, numero de queda e alveografia. Os biscoitos foram elaborados de acordo com metodo da AACC e avaliado volume especifico, diâmetro, espessura, fator de expansao e cor. A metodologia utilizada no laboratorio para a elaboracao de biscoitos tipo semi-duros e adequada para a avaliacao de uso final de farinhas de trigo. Com base nas propriedades funcionais, as farinhas de trigo dos cultivares BR 23, BRS 120 e BRS 176 foram as mais recomendadas para a producao de biscoitos.

Avaliação dos teores de fibra alimentar e de beta-glicanas em cultivares de aveia (Avena sativa L)

A fibra alimentar e composta por celulose, hemiceluloses, gomas, pectinas e mucilagens sendo classificada em soluvel e insoluvel, quanto a sua solubilidade em agua. As beta-glicanas sao componentes da fibra alimentar soluvel presentes na aveia e sua importância e devido as propriedades funcionais e aos efeitos hipocolesterolemicos e hipoglicemicos apresentados. O presente trabalho tem como objetivo avaliar os teores de fibra alimentar soluvel, insoluvel e total e de beta-glicanas de cultivares de aveia recomendados pela Comissao Brasileira de Pesquisa de Aveia. Graos de aveia (Avena sativa, L) foram descascados, as cariopses moidas e as amostras acondicionadas e armazenadas a temperatura de -20° C. Para a analise de fibra alimentar foi adotada a metodologia da AOAC (1997). Entre os cultivares analisados, UPF 7, UPF 13, UPF 14 e UPF 16 apresentaram os maiores teores de fibra alimentar insoluvel. Os maiores teores de fibra alimentar soluvel foram verificados nos cultivares UFRGS 7, CTC 13, UPF 16 e CTC 2. O cultivar UPF 16 apresentou o maior teor de fibra alimentar total, seguido de UFRGS 7, CTC 13 e UFRGS 18. Para a determinacao de beta-glicanas foi adotada a metodologia da AOAC (1997). Os maiores teores de beta-glicanas foram verificados nos cultivares UFRGS 7, UPF 14 e UFRGS 18.

Qualidade industrial do trigo em resposta à adubação verde e doses de nitrogênio

The objective this study was to investigate the effects of green manures cultivated between the maize and wheat crop and nitrogen rates on baking quality of spring wheat. Treatments consisted of four nitrogen fertilization rates: without N addition, 40, 80 and 120 kg ha-1 using the amidic form, and six managements before wheat crop: four green manures forage pea, common pea, oilseed radish and lupine, common bean grown for commercial purposes, and the fallow between the corn harvest and wheat cropping. The experimental design was in randomized blocks and factorial scheme, with three replicates. The protein yield increased linearly with the application of mineral N rates. The nitrogen rates of 80 and 120 kg ha-1 improved the baking wheat quality. The forage pea, oilseed radish and common pea allowed ideal index of baking quality and satisfactory crop yield, reducing the demand for mineral N fertilization.

Efeito do período de maturação de grãos nas propriedades físicas e reológicas de trigo

The aim of this study was to investigate the effect of the maturation period of grains on the physical and rheological properties of wheat flour analyzed by determining the hectoliter weight, weight of thousand grains, experimental milling, proteins, ashes, moisture, color, falling number, alveography, farinography, and damaged starch. Samples of genotypes BRS 179, Rubi, Fundacep 30, Fundacep 51, and 2006/2007 crop, were stored in Kraft paper bags with 10 kg of wheat, at environment temperature of 22 oC and air humidity between 65-75%. Each treatment consisted of one genotype and the measurements were made at zero, 15, 30, 60, and 90 days of maturation. The experiment was carried out in fully randomized factorial design at 4 x 5. The results were analyzed by variance analysis (Anova) and the means compared by Tukeys test at 5% probability. With the increase in the maturation period of wheat, the flour presented the best physical and rheological properties assessed by the changes of the falling number, color, alveography, and farinography. The results of the enzymatic activity, luminosity, yellow intensity, and general gluten strength were effective in the evaluation of physical and rheological properties while the assessments of damaged starch and stability were not appropriate indicators. The wheat should not be sold after harvest, since its commercial classification improvement indicates a maturation period of 60 days. The genotypes of wheat BRS 179 and Fundacep 51 genotypes changed from bland to bread and from Rubi bread to improved indicating higher technological and commercial value with the increase in the maturation period of the wheat grains.

Efeito da umidade e do período de armazenamento hermético na contaminação natural por fungos e a produção de micotoxinas em grãos de aveia

Com o presente trabalho, objetivou-se avaliar a contaminacao natural por fungos, producao de micotoxinas, composicao em acidos graxos e concentracao de CO2 intergranular em graos de aveia armazenados no sistema hermetico por 12 meses. Graos de aveia, da cultivar UPF 18 foram colhidos com 16% de umidade e realizado a secagem estacionaria em prototipo silo-secador ate as umidades de 15%, 12% e 9%. Para os tratamentos com 18% e 21% de umidade foi realizada a reidratacao pela colocacao dos graos em atmosfera saturada por cinco dias. Determinou-se a composicao centesimal aproximada, composicao em acidos graxos, contaminacao natural por fungos, presenca de micotoxinas e concentracao de CO2 intergranular. Os resultados foram analisados pela analise de variância, comparacao de medias pelo teste de Tukey e analise de regressao. Nao foi detectada a presenca das micotoxinas aflatoxina B1, B2, G1, G2, zearalenona e ocratoxina A. A quantidade de CO2 na atmosfera intergranular apresentou comportamento linear e foi proporcional a umidade dos graos e tempos de armazenamento. O aumento do tempo de armazenamento e da umidade dos graos intensificou a reducao de acidos graxos insaturados, com predominância de acao sobre linoleico e linolenico.

Caracterização química de cariopses de aveia (Avena sativa L) da cultivar UPF 18

This research was aimed to determine the chemical characteristics of the new oat cultivar UPF 18, which became recommended by the Brazilian Oat Research Committee in 1999. Oat grains from the 1999 cropping season were dehulled, the caryopses ground to a granulometry below 0.250mm, and the resulting flour evaluated regarding its composition, amount of amino and fatty acids, index of solubility in nitrogen, in vitro protein digestibility, chemical score, and metabolizing energy. The cultivar UPF 18 presented a high protein content (15.07%). The levels of soluble (5.59%) and insoluble (7.73%) dietary fiber were also high, making the amount o starch low (41%). The amino acid composition was similar to the FAO theoretic standard in most of the amino acids, where lysine was the first limiting. This cultivar also showed high levels of unsaturated fatty acids, with linoleic, oleic, and palmitic acids representing 96.06% of the total. The in vitro protein digestibility reached 98.86%, the chemical score 52.2%, and the metabolizing energy 326.56 kcal/100g.

Combining ability for grain chemistry quality traits in a white oat diallelic cross

There has been a strong demand for oat genotypes that contain caryopsis with high chemical quality which can suit the different market niches. Therefore, the objectives of this study were to assess the general (GCA) and specific combining ability (SCA) of white oat cultivars through diallelic crosses providing information about the genetic effects on expression of grain chemical quality components. Also, it was aimed to estimate the heterosis on F1 and F2 generations and the vigor loss due to inbreeding. During 2008, 21 hybrid populations F1 and F2 were obtained from artificial crossing among seven Brazilian white oat cultivars, following the complete diallel design, without considering the reciprocals. These populations and their parents were evaluated in the 2009 season in the experimental field in Capão do Leão, RS, Brazil. The higher values of mean squares associated to GCA indicates a strong contribution of additive genetic effects to the expression of grain chemical components. The parents tested showed a tendency to develop progeny with negative heterosis regarding protein, lipid, β-glucan and soluble dietary fiber in the grain, and positive for the content of nitrogen-free extract, total and insoluble dietary fiber. IAC 7 features a potential parent for obtaining grains with high protein and dietary fiber content, and low caloric content, fit to human diet. Meanwhile, UPF 15 and FAPA Louise can represent donors of alleles to increase lipid contents, while FAPA Louise and URS Guapa can be used to raise the grain nitrogen-free extract contents of lines intended for animal feeding.