Nutrientes e propriedades funcionais em sementes de abóbora (Cucurbita maxima) submetidas a diferentes processamentos

O objetivo deste trabalho foi verificar a influência dos processamentos térmicos sobre os nutrientes e propriedades funcionais das sementes da abóbora Cucurbita maxima. As sementes foram, em quatro repetições, submetidas aos seguintes processamentos: utilizadas na forma crua; cozidas em água em ebulição por três tempos: 5, 10 e 15 minutos; e cozidas no vapor por 10 minutos. Posteriormente foram liofilizadas, trituradas e armazenadas em temperatura ambiente até a realização das análises de composição centesimal, minerais e propriedades funcionais. Não houve diferença significativa entre os processamentos para os níveis de proteína bruta, fibra alimentar, extrato etéreo, cinzas, S, P, Mg, Ca, Cu, Zn, solubilidade do nitrogênio (nos pH 4, 5 e 6), absorção de água e óleo, volume de espuma e estabilidade de emulsão. O cozimento em água em ebulição reduziu o teor de K. Todos os processamentos térmicos diminuíram os níveis de Mn e Fe. As sementes cruas apresentaram a maior solubilidade do nitrogênio nos pH 2, 3, 7, 8 e 9. Conclui-se que os processamentos acarretaram diferença significativa apenas nos teores de K, Mn, Fe e solubilidade do nitrogênio; e que as sementes apresentam potencial para serem incorporadas, provavelmente, em alimentos que requeiram elevada taxa de absorção de óleo.

Alterações químicas em grãos de soja com a germinação

A soja apresenta importância comercial e nutricional, embora apresente fatores que possam diminuir o aproveitamento de nutrientes. A germinação tem efeito positivo na melhora nutricional do grão, pois ocorrem mudanças, as quais variam dependendo do tipo do vegetal, da variedade da semente e das condições da germinação. O trabalho teve por objetivo analisar grãos de soja antes e após germinação de 48 horas. Para isso foram quantificados: composição centesimal, inibidores de tripsina, ácido fítico, taninos, fenólicos totais, teor de ferro, disponibilidade de ferro in vitro, digestibilidade da proteína e atividade antioxidante (pelos métodos DPPH e ABTS). A germinação apresentou efeito na composição química e disponibilidade de proteínas e de ferro. Em relação aos teores de taninos, carboidratos disponíveis e atividade antioxidante pelos métodos DPPH e ABTS, houve redução significativa. O processo de germinação promoveu aumento do teor de umidade, lipídio, proteína, fibra solúvel, digestibilidade in vitro de proteína e fenólicos totais. Não apresentou diferença estatística para os teores de cinzas, fibra insolúvel, disponibilidade e teor de ferro, ácido fítico e atividade inibitória de tripsina. Apesar do período curto de germinação utilizado (48 horas) ocorreram mudanças em sua composição que foram satisfatórias, proporcionando aumento da qualidade nutricional.

Disponibilidade de cálcio em leite bovino tratado por raios gama

O leite bovino é um alimento de grande importância com fonte de cálcio e proteínas. O objetivo deste trabalho foi o de avaliar os efeitos da radiação gama proveniente do 60Co sobre a disponibilidade de cálcio e o aspecto sensorial. O leite utilizado foi embalado em sacos para leite conforme o encontrado no comércio. As amostras foram submetidas à radiação gama nas doses 0,1, 0,5, 1,0, 2,0 e 3,0 kGy e ficaram armazenadas a 4 °C, e suas avaliações ocorreram nos 1º, 4º, 7º e 10º dias de armazenamento. Foi avaliado o teor de cálcio e a composição centesimal do leite logo após sua obtenção. A diálise de cálcio in vitro foi realizada nos diferentes tempos de armazenamento. Nas duas doses, com pH mais estável na menor dose de radiação e uma dose abaixo, 0,5 e 1,0 kGy, foi realizada análise sensorial. A análise dos dados foi feita empregando teste de Tukey (5%). Quanto à análise físico-química, as amostras irradiadas melhoraram a disponibilidade do cálcio sendo a dose mais adequada a de 1 kGy devido a sua maior estabilidade do pH no período de 10 dias, porém sensorialmente as amostras não foram bem aceitas.

Disponibilidade de ferro, digestibilidade de proteína e teor de β-caroteno em formulados alternativos de baixo custo para alimentação enteral de idosos

O objetivo geral deste trabalho foi elaborar formulados alternativos à base de mistura de alimentos convencionais provenientes da cesta básica distribuída por entidades do município de Piracicaba-SP, entre outros alimentos, com o intuito de suplementar a alimentação enteral de idosos. Os alimentos utilizados para elaboração dos formulados foram fubá, óleo de soja, arroz, feijão, macarrão, sardinha, leite em pó, amido de milho, ovos, proteína texturizada de soja, couve-manteiga e cenoura. Foram realizadas análises químicas: composição centesimal, digestibilidade de proteína, determinação do mineral ferro, diálise de ferro in vitro, determinação de β-caroteno e fatores antinutricionais, assim como fenólicos totais e ácido fítico; e análise de custos dos formulados. Os resultados obtidos foram submetidos às análises estatísticas empregando o teste de Tukey e análises de regressão. Concluiu-se com este estudo que os formulados líquidos apresentaram os melhores resultados nutricionais e viabilidade econômica. Dentre estes, podem-se eleger duas alternativas. O formulado F3 se destacou na disponibilidade de ferro, quantidades de β-caroteno e digestibilidade. O formulado F4 se destacou na distribuição do valor calórico total de macronutrientes. Os formulados contribuem com percentual médio de 20% de adequação para idosos, quando ingeridas duas porções de 250 mL/dia de formulados líquidos ou em pó.

Effect of the daily consumption of ostrich and bovine meat on the lipid metabolism in rats

The objective of this study is to evaluate the effect of the daily consumption of ostrich meat (lliofemuralis internus) and bovine meat (Psoas major) on the lipid metabolism in adult mice. The analyses of the centesimal composition of the meats and preparation of the diets were accomplished following the recommendations of the American Institute of Nutrition-AIN-93. Three groups of 150 day-old animals: group I (diet I, with casein), group II (diet II, with ostrich meat), and group III (diet III with bovine meat) were fed for 13 weeks with the respective diets and weight gain, food efficiency coefficient, total cholesterol, lipoprotein fractions, hepatic, transaminases and body fat percentage and hepatic fat content were evaluated. No difference (p < 0.05) it was found for weight gain and coefficients for feed efficiency among the groups. Total cholesterol, HDL-cholesterol, LDL-cholesterol, relationship of total cholesterol/HDL-cholesterol, VLDL, triglycerides and hepatic transaminases were also not different among the groups (p < 0.05). This research suggests that the consumption of ostrich meat or thin bovine meat on a daily basis does not raise concerns about weight gain, and an increase in the plasma concentrations of lipoprotein and levels of hepatic transaminase.

Proximate composition and quantification of fatty acids in five major Brazilian chocolate brands

The objective of the present study was to characterize the centesimal composition and quantify fatty acids in regular and diet chocolate brands with emphasis on trans fatty acids. Regular and diet dark chocolate samples from the major brands analyzed were purchased from different local supermarkets in the city of Maringá. The brands were labeled with letters and five lots of each brand with three chocolate units per lot were analyzed in triplicate. We observed that the diet chocolates from the same brands presented larger lipid contents. The main fatty acids observed were saturated fatty acids (SFA), myristic acid (14:0), palmitic acid (16:0), and estearic acid (18:0). Among the monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) and trans fatty acids, oleic acid (18:1n-9), linoleic acid (18:2n-6), and elaidic acid (18:1-9t) predominated. The trans fatty acid contents found in the analyzed samples were lower than and/or in accordance with the limits proposed by the Brazilian regulation.

Sensory and microbiological evaluation of uncured fresh chicken sausage with reduced fat content

The purpose of this study was to evaluate the acceptability and the microbiological safety of uncured fresh chicken sausages with reduced fat content, considering the scientific evidence that correlated cancer and cardiovascular diseases to this diet. Two formulations of uncured fresh chicken sausage were processed using different concentrations of cochineal carmine pigment, rosemary extracts and synthetic antioxidants, which are used to give color, appearance and pleasant flavor to the products. Then, instrumental color (L*, a*, b*, C* and h*), microbial contamination and sensory tests (ranking and acceptance) were used to evaluate the quality of the uncured chicken sausages. The instrumental color (chroma and hue) and the sensory properties of the A and B uncured sausages were similar to the commercial cured sausage (C). However, the sensory color and appearance of samples A and B were statistically higher than those of the commercial uncured sausages D, which are prepared without the addition of nitrite or pigments. The results showed that it is possible to produce safe and high-quality uncured fresh chicken sausage with reduced fat content, using natural pigments and antioxidants.

Study of the flash drying of the residue from soymilk processing - "okara"

The objective of this research project was to study the drying of soymilk residue in a pneumatic flash dryer, using response Surface Methodology (RSM), and to evaluate the quality of the dried residue. Soymilk residue, also known as okara, was provided by a Brazilian soymilk factory. RSM showed that for a 120 second drying cycle, the lower the residue moisture contents (y) obtained, the higher the recirculation rates (x1), regardless of the air drying temperature (x2), and it could be expressed by the equation y = 7.072 - 7.92x1, with R² = 92,92%. It is possible to obtain okara with 10% of moisture (dwb) under the condition x1=1.25, equivalent to RR = 61%, with air drying temperatures ranging from 252 °C to 308 °C. The dried okara obtained through Central Compound Rotational Design (CCRD) presented a centesimal composition similar to the okara dried in a tray dryer, known as the original okara. There were significant variations (p < 0.05) in the Emulsifying Capacity (EC), Emulsion Stability (ES) and Protein Solubility (PS) between the dehydrated residues obtained. It was concluded that the flash drying of okara is technically feasible and that the physicochemical composition of the residue was not altered; on the contrary, the process promoted a positive effect on the technological functional properties.

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.

Sugar fractionation and pectin content during the ripening of guava cv. Pedro Sato

Guava is one of the most complete and balanced fruits in in terms of s nutritional value. Highly perishable, due to its intense metabolism during ripening, its shelf life can reach 3 to 5 days under room temperature. The firmness of the green and mature fruits is due mainly to the pectin polymers. The loss of firmness during the guava ripening is due to hydrolytic enzyme activity, which promotes intense solubilization of the cell wall pectins. Given the above, with the purpose of trying to explain the rapid firmness decrease, the centesimal composition and sugar fraction of the guava fruit were determined during ripening at room temperature. The guavas were picked at the half-mature stage and stored for 8 days at 22 ± 1 ºC and 78 ± 1% relative humidity. The analyses conducted were: centesimal composition, sugar fractionation, and infrared absorption spectrometry. The results showed that the guava sugars did not vary during ripening. The estimated pectin levels (5.7%) were higher than those mentioned in the literature (2.4%), which can better explain the role of the pectin in the fruit firmness.

Effect of harvest at different times of day on the physical and chemical characteristics of vegetable-type soybean

The objective of this study was to evaluate the effect of harvest at different times of day on the chemical and physical characteristics of vegetable-type soybean BRS 267 cultivar, harvested at the R6 stage (seed development) and to compare it with that on the grains harvested at the R8 stage (maturation). The pods of the BRS 267 cultivar were harvested at the R6 stage (at 8:00 AM, 12:00 AM, and 6:00 PM), the color parameters were evaluated, and the grains were analyzed for chemical composition, activity inhibitor trypsin, phytic acid content, starch, sugars, fatty acids, and isoflavones. No differences were observed among the different harvest times in terms of the chemical constituents of vegetable-type soybean BRS 267 cultivar harvested at the R6 stage. Isoflavones content did not change with different harvest times, and the aglycone forms (daidzein, glycitein, and genistein) were found in smaller quantities at the R6 stage compared to the R8 stage. The color of the pods of soybean BRS 267 cultivar, harvested at the R6 stage did not change with different harvest times. The grains harvested at the R6 stage had lower protein content, phytic acid, and sucrose and higher levels of lipids, carbohydrates, starch, glucose, fructose, stachyose, and linolenic acids than those collected at the R8 stage. The different times of harvest did not affect the quality of the vegetable-type soybean BRS 267 cultivar harvested at stage R6. Nevertheless, it is recommended to harvest in the morning, when the temperature is milder, like other vegetables, to facilitate and optimize its marketing and in natura consumption.

Studies of chemical and enzymatic characteristics of Yacon (Smallanthus sonchifolius) and its flours

Due to the importance of studies on yacon related to health, its in natura pulp, in natura peel, pulp flour, and peel flour were chemically analyzed in terms of its centesimal composition, specific minerals, total dietary fiber and fractions, pH, total soluble solids, total titratable acidity, tannins, oxalic acid, and nitrate. The polyphenoloxidase and peroxidase enzymatic activities were evaluated for in natura pulp and peel only. Yacon pulp and peel flour presented average yield of 7.94% and 10.86%, respectively. The in natura pulp presented a higher moisture and carboydrate content and lower lipid, protein, total dietary fiber, and ash than those of the peel flour. The same pattern was observed for pulp flour when compared to peel flour. The highest tannin, nitrate, and oxalic acid levels were found in the peel flour, 15,304.5 mg.kg-1, 1,578.3 mg.kg-1, and 7,925.0 mg.kg-1 (wet weight), respectively. The polyphenoloxidase and peroxidase enzymes presented higher enzymatic activity in the yacon peel. Based on the results obtained, it can be said that the yacon and its derivatives are important dietary carbohydrate and mineral sources and contain antinutritional substance contents lower than those harmful to health.

Adubação orgânica e mineral na produção, qualidade e composição química de sementes de abobrinha (Cucurbita pepo L. var. melopepo cv. Caserta)

Com o objetivo de estudar os efeitos da adubação sobre os componentes do rendimento, no potencial de produção, qualidade e composição química das sementes de C. pepo L variedade melopepo (Caserta) conduziu-se dois Estudos no Centro Agrícola Demonstrativo da Prefeitura de Porto Alegre/CAD, e no Laboratório de Análise de Sementes do Departamento de Plantas forrageiras e Agrometeorologia da Faculdade de Agronomia da Universidade Federal do Rio Grande do Sul (UFRGS) nos períodos de 2000/01 e 2002/03. No primeiro estudo utilizou-se dois tipos de adubação uma orgânica (cama de aviário- 386g/cova), e outra mineral (fórmula 5-20-20). No segundo estudo, os tratamentos constaram de:T1= testemunha, T2= adubação mineral, e 4 doses de cama de aviário: T3= 63g/cova, T4= 125 g/cova, T5= 187g/cova, T6= 250g/cova. O delineamento experimental foi o de blocos casualizados com 4 e 3 repetições no primeiro e segundo estudos, respectivamente. Foram determinados: número de flores/planta, número de frutos/planta, peso médio de frutos, peso de sementes/fruto, número de sementes/fruto, peso de 1000 sementes, rendimento de sementes/área, germinação, emergência em campo, teste de frio, condutividade elétrica, comprimento de plântula, composição centesimal (Cinza, PB, EE, FB, ENN, NDT, EB, MO), macronutrientes (N, P, K, Ca, MG, S) e micronutrientes (Cu, Zn, Fe, Mn, Na, B). No primeiro estudo, tanto a adubação mineral como a adubação orgânica não afetaram os componentes do rendimento, o rendimento/área, a qualidade e a composição química de sementes. No segundo estudo, a aplicação de cama de aviário aumentou o rendimento de sementes de abobrinha e os teores de nitrogênio e ferro nas sementes, porém não afetou a qualidade. A dose de cama de aviário que proporcionou o melhor resultado foi de 250g/cova (3,12 t/ha).

Prêmio por controle no mercado brasileiro

Este trabalho visa estimar o prêmio por controle no mercado acionário brasileiro, com base no diferencial de preços entre espécies de ações com direitos diferenciados de voto. Mostramos primeiro que, entre 01/07/2003 e 28/06/2013, o prêmio médio por controle é positivo, contrariando resultados anteriores da literatura. Investigamos então os determinantes da diferença entre os preços das ações ordinárias e preferenciais. Em particular, analisamos a relação do prêmio por controle com a liquidez relativa, o diferencial de dividendos, a extensão ou não do direito de tag along para ações preferenciais, a emissão ou nao de ADR na Bolsa de Valores de Nova Iorque, o nível de governança corporativa, a composiao acionária e, em especial, a participação acionária do governo nas empresas.

Enrichment of bioactive compounds in microalgae for aquaculture

Microalgae are promising microorganisms for the production of food and fine chemicals. Several species of microalgae are used in aquaculture with the purpose of transfer bioactive compounds up to the aquatic food chain. The main objective of this project was to develop a stress–inducement strategy in order to enhance the biochemical productivity of Nannochloropsis gaditana, Rhodomonas marina and Isochrysis sp. for aquaculture purposes having in account their growth and organizational differences. In this regard, two experiments were design: the first one consisted on the alteration of overall nutrient availabilities in growth medium; and the second one comprised changes in nitrogen and sulfur concentrations maintaining the concentrations of the other nutrients present in a commercial growth medium (Nutribloom plus), which is frequently used in aquaculture. Microalgae dried biomass was characterized biochemically and elemental analysis was also performed for all samples. In first experimental design: linear trends between nutrient availability in growth media and microalgae protein content were obtained; optimum productivities of eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) were attained for both R. marina and N. gaditana in growth media enriched with 1000 L L-1 of nutrient solution whereas for Isochrysis sp. the double of Nutribloom plus was needed; the decrease of glucans and total monosaccharides with nutrient availability for R. marina and Isochrysis sp. showed the occurrence of a possible depletion of carbohydrates towards lipids and proteins biosynthesis. Second experimental desing: N. gaditana exhibited the highest variation in their biochemical composition against the applied perturbation; variations observed for microalgae in their biochemical composition were reflected in their elemental stoichiometry; in N. gaditana the highest nitrogen concentrations lead to overall maximum productivities of the biochemical parameters. The results of the present work show two stress-inducement strategies for microalgae that may constitute a base for further investigations on their biochemical enhancement.