Qualidade fisiológica de sementes de palmiteiro-vermelho em função da desidratação e do armazenamento

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da geometria e da temperatura na cinética de secagem de tomate (Lycopersicum esculentum)

O tomate é um fruto muito perecível por causa do seu conteúdo de umidade. A secagem é uma das práticas industriais mais utilizadas em alimentos para manter a qualidade do produto final. A pesquisa foi desenvolvida para estudo dos parâmetros de secagem de tomate (Lycopersicon esculentum Mill), cv Carmen, com relação ao tipo de corte (meio e um quarto) e à temperatura de processo (60 e 70 ºC), bem como à escolha do tempo de secagem para a obtenção de um produto com umidade de 45% (base úmida). As cinéticas de secagem foram determinadas experimentalmente por convecção forçada e ajustadas ao modelo de Page. Os resultados obtidos mostraram que a geometria de corte influenciou na taxa de secagem e no tempo de desidratação. Os tomates cortados em quatro partes e desidratados a 70 ºC alcançaram umidade de 45% em menor tempo (10 horas), quando comparados aos tomates com o corte em metades. O modelo de Page forneceu bom ajuste nas cinéticas de secagem

Influence of osmotic dehydration on ascorbic acid loss in pickled dry peppers (Capsicum chinense)

The objective of this work was (1) to develop a dehydrated pepper with 45% humidity, determining the drying curves for pepper, with and without osmotic pre-treatment and (2) to evaluate the influence of both drying and osmotic treatment on the content ascorbic acid (vitamin C) in fresh pepper and pepper with 45% humidity. The experiments were carried out using the peppers cut in half, with and without osmotic pre-treatment, followed by drying in an oven at 70 ºC. The results showed that the osmotic pretreatment did not influence the retention of ascorbic acid during the drying of pepper. The sensory analysis regarding the color, flavor, and texture attributes revealed that there was no difference in the acceptability.

Influência do método de fenação e tempo de armazenamento sobre a composição bromatológica e ocorrência de fungos no feno de alfafa (Medicago sativa, L. cv. Flórida 77)

O experimento objetivou estudar a influência de 24 tratamentos resultantes do arranjo fatorial 6 x 4, referente a seis métodos de fenação e quatro tempos de armazenamento em delineamento inteiramente casualizado, com cinco repetições para análise bromatológica e quatro para determinação de fungos. Os métodos de fenação consistiram em: T1 - (sombra, E) secagem à sombra, a forrageira foi levada para o galpão imediatamente após o corte e mantida espalhada (E); T2 e T3 - o material permaneceu ao sol até perder 50% do peso e posteriormente foi seco à sombra, sendo o T2 espalhado (sol 50%, E) e o T3 amontoado - A (sol 50%, A); T4 e T5, consistiram do recolhimento da forragem para completar sua secagem à sombra, após viragem e perda de 60% de peso sob exposição ao sol, T4 espalhada (sol 60%, E), T5 amontoada (sol 60%, A) e o T6 perda de 80% do peso sob exposição ao sol e posteriormente amontoado à sombra (sol 80%, A). Os quatro tempos de armazenamento foram: 0, 15, 30 e 60 dias. Verificou-se que os fenos nos quais o material ficou mais tempo exposto ao sol apresentaram pior qualidade em termos de PB, FDN e FDA. A ocorrência de fungos foi maior no feno seco à sombra (T1) e naqueles em que a forragem foi amontoada, devido à ausência de aeração para retirada de umidade. O método mais adequado para a conservação da alfafa consistiu na exposição da forragem ao sol até a perda de 50% do peso da forragem original, com posterior secagem do material espalhado à sombra.

Evaluation of new red winemaking technologies through consumer liking

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

INFLUENCE of ENCAPSULATING MATERIALS on WATER SORPTION ISOTHERMS of VACUUM-DRIED PERSIMMON PULP POWDER

Water sorption isotherms for vacuum-dried persimmon pulp (PP) powder were determined in the temperature range of 20-50C, and the effects of maltodextrin (MD) or gum arabic (GA) addition on the water sorption behavior of the dried powders were analyzed. Several models were evaluated to fit the experimental data and the Guggenheim-Anderson-de Boer model was selected as the most adequate to describe the observed behavior. Addition of encapsulants affected the isotherms: at the same water activity, PP powder with added GA (PP + GA) or MD (PP + MD) presented lower equilibrium water content than pure PP and were less affected by temperature variations. Samples of PP + MD presented lower equilibrium moisture content than those of PP + GA. The isosteric heats of sorption of pulp powders with encapsulants were higher (less negative) than those of PP, suggesting that there are more active polar sites in PP than in pulp powder containing encapsulants.PRACTICAL APPLICATIONSThe choice of persimmon to carry out this work was due to the large persimmon production available in Brazil; moreover, persimmon pulp is rich in vitamin C, vitamin A and iron, as well as in phenolic compounds. Drying of fruit pulps with high sugar content presents technical difficulties because the hygroscopicity and thermoplasticity of the resulting powders when exposed to high temperature and relative humidity. For this reason, addition of high-molar-mass biopolymers, such as maltodextrin or gum arabic, is a strategy to aid drying and to improve storage stability. Knowledge of water sorption isotherms and net isosteric heats of sorption is important to various food processing operations, including drying, storage and packaging. They are useful in calculating time and energy consumptions during drying, modeling moisture changes during storage and predicting shelf life of food products.

Adaptações em forno de microondas doméstico para utilização em laboratório

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Secagem e armazenamento de sementes de juçara

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da perda da tolerância à dessecação e da quantidade de dna nuclear em sementes de Peltophorum dubium (spreng.) taubert durante e após a germinação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Chemical Percolation Devolatilization Model Applied to the Devolatilization of Coal in High Intensity Acoustic Fields

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mineralogical characterization of clays used in the structural ceramic industry in west of S. Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualidade do café natural e despolpado após secagem em terreiro e com altas temperaturas

Objetivou-se no presente trabalho verificar a qualidade do café natural e despolpado durante a secagem em terreiro e secagem com ar aquecido a 40º e 60ºC. O trabalho foi realizado no Departamento de Engenharia e no Pólo de Tecnologia em Pós-Colheita do Café da Universidade Federal de Lavras (UFLA). A colheita do café, cultivar Topázio, foi seletiva. Parte do café foi despolpado e outra parte processado de forma natural. Uma parcela de cada tipo de café foi conduzida para a secagem em terreiro e outra parcela para secagem com temperaturas de 40ºC e 60ºC. Para avaliação da qualidade, foram feitos teste de condutividade elétrica e lixiviação de potássio; determinação de acidez titulável total; teste de acidez graxa; açúcares totais e redutores. Os resultados obtidos permitem concluir que: o tempo para secagem é afetado pelos diferentes tipos de secagem e processamentos; a condutividade elétrica, a lixiviação de potássio, a acidez titulável total e a acidez graxa aumentam com a elevação da temperatura de secagem, independente do tipo de processamento; os açúcares redutores e os açúcares totais diminuem com o aumento da tem peratura de secagem independente do tipo de processamento; a secagem com temperatura de 60ºC afetou negativamente a qualidade do café.

Variação espaço-temporal na distribuição e abundância de Moenkhausia sanctaefilomenae (Characiformes: Characidae) em lagoas da planície de inundação do rio Cuiabá, Pantanal, Brasil

Identifying the biotic and abiotic factors that determine the variation in the distribution and abundance of populations has become a great challenge for the field of ecology in recent years. Thus, in this study we evaluated the effect of abiotic variables and the abundance of predators on the abundance of Moenkhausia sanctaefilomenae, the variation in the average length of the individuals between lakes and periods, and the effect of the abiotic variables and abundance of predators on the structure in length of that species. Sixteen lakes of the Cuiaba river flood plain were sampled in June (drying period), September (dry period) and December (flooding period) 2005 and March (flood period) 2006. For M. sanctaefilomenae, the distribution is ampler and the abundance is greater at the end of the drying period, beginning of dry season, reducing gradually over the periods of dry, drying and flood season. Additionally, the period affects the structure in size of the populations that are spatially homogeneous. Smaller individuals were captured at the end of the drying period and the larger individuals at the start of flooding. During the end of the drying period and in the beginning of the dry season, the spatial variation in the abundance of the population was positively related with pH, dissolved oxygen and macrophyte cover and area of the lake, but not with the local abundance of predators in the littoral zone of the lakes.

SEM analysis of internal adaptation of adhesive restorations after contamination with saliva

Purpose: This study tested the null hypothesis that different treatments of saliva-contaminated substrate would not affect microgap formation at the dentin walls of bonded restorations. Materials and Methods: Forty freshly extracted human molars received standardized Class V preparations on buccal and lingual surfaces. The specimens were assigned to four experimental groups (n = 20): [G1] no contamination (control group), [G2] saliva contamination (10 s) after etching followed by 5 s air stream; [G3] saliva contamination after etching and rinsed for 10 s; and [G4] re-etching for 10 s after saliva contamination. All specimens were restored with a one-bottle adhesive (Single Bond, 3M ESPE) and microhybrid composite resin (Filtek Z250, 3M ESPE) according to the manufacturer's instructions. The specimens were thermocycled, sectioned through the center of the restoration, and then processed for SEM. Microgaps were measured at the axial wall at 1500X magnification. The data were submitted to Kruskal-Wallis nonparametric statistical analysis at p < 0.05. Results: The data revealed that different groups resulted in a statistically significant difference (p < 0.01) in gap formation. Air drying [G2] and rinsing [G3] the saliva-contaminated dentin resulted in similar microgap values (p > 0.05). However, re-etching the dentin after saliva contamination [G4] increased microgap formation (p < 0.05) when compared with the groups G1 and G2. Although air drying and rinsing produced results comparable to noncontaminated dentin, the presence of microgaps was not completely eliminated. Conclusion: Contaminated saliva did not prevent hybrid layer formation; however, it did reduce the adaptation of the restorative material to bonded surfaces.

Influência da granulometria de grânulos de amido sobre a densidade aparente de extratos atomizados

Starches and modified starch derivations are used as carriers in the spray drying processing where apparent density is an important characteristic and should be controlled in dehydrated products for pharmaceutical use. In Brazil, the commercial starches are made from corn and cassava, but there are others with potential for extraction. The canna and taro starches were selected because they represent the extremes of granule size and thus allow the effect of this size on the apparent density of spray dried products to be tested. For comparison, commercial cassava and corn starches which are used in spray-drying and have granules of intermediate size, were also tested. The spray-drying process was carried out with a LabPlant SD 04 Spray Dryer, operating at a pressure of 6 lb/in2, air of 7,6 mL/minute, and 1 cm atomizing nozzle. The air inlet temperature was set at 200°C this model does not allow regulating outlet temperature. The spray-dryer products had boldo leaf extract as base, using the four starches as carrier. The dry product was evaluated for humidity, water activity (Aw), granulometry and apparent density. The results showed that the size of the particles, which was a consequence of the size of the starch granules, influenced the apparent density of the spray dried products, which as higher (694, 27 g/mL) for the canna starch and lower (456, 13 g/mL) for taro starch. Corn and cassava starches showed very close and intermediate values, 521,51 and 58,48 g/mL, which also represent the standard range of starch granule size.