Desidratação de sementes de quatro lotes de pupunheira: efeitos sobre a germinação e o vigor

Com o objetivo de verificar o efeito da desidratação sobre a germinação e o vigor de sementes de pupunheira inerme (Bactris gasipaes Kunth), quatro lotes de sementes, colhidos nas localidades de Yurimaguas, Peru; Camamu e Piraí do Norte, BA e Pindorama, SP, foram submetidos à secagem em câmara seca a partir das testemunhas não desidratadas, retirando-se amostras a cada 24 horas. O efeito da desidratação sobre a qualidade das sementes foi avaliado por meio de teste de germinação (184 dias da semeadura, em vermiculita, 20-30ºC), primeira contagem de germinação (36 dias), velocidade de germinação e teor de água das sementes. Comprovou-se que sementes dessa espécie são sensíveis à desidratação, com germinação inicial alta (59 a 84%) quando não desidratadas (47 a 38% de umidade inicial). Teores de água abaixo da faixa de 28 a 23% reduziram significativamente a germinação e o vigor. Todas as sementes com teores de umidade abaixo de 15% (lotes 2 e 4) e 13% (lotes 1 e 3) morreram.

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)

Estudo da desidratação de tomates em pedaços com pré-tratamento osmótico

Vegetables drying plays an important role in the field of food dehydration, being a very old practice that was originated from sun drying items of food in order to preserve them to be consumed during the periods of scarcity. One of these vegetables is the tomato, that was originally grown in South America. Tomatoes are easily perishable after being picked up from the tree and this makes the process of tomato dehydration a challenge due to the high amount of water (95%) contained in them. The present research work was mainly intended to develop alternative processes for tomato conservation, by drying slices of skinned and unskinned tomatoes in the in natura form or in the osmotically pre-dehydrated form. Firstly, the best conditions of the osmotic pre-dehydration process were defined including temperature, immersion time and concentration of the osmotic solution, based on the results of water loss, solids gain and weigh reduction of the pre-dehydration tomatoes at different processing conditions. The osmotic solution used was made up of NaCl (5 and 10%) and sucrose (25 and 35%) at different combinations. For a fixed conditions of osmotic pre-dehydration, the drying tests of the pre-processed and in natura tomatoes were carried out in a stove with air circulation and a convective dryer with trays, at two levels of temperature. The sensorial analysis of the osmotically pre-treated and unskinned dehydrated tomatoes was carried out as well as a study on the their shelf-live. The results obtained showed that the drying of the tomatoes took place as a result of the internal control of the water transport, and did not show a constant rate, while two distinct periods of the decreasing phase were observed. The osmotic pre treatment substancially reduced the initial amount of humidity in the tomatoes, thus reducing the necessary time for the product to attain levels of intermediate humidity. The impermeability of the tomato skin was identified as well as the unfavorable influence of the pre-treatment on the unskinned tomatoes, whose solid gain brought about a decrease in the water activity with subsequent reduction of the drying rate. Despite the various simplifications carried out during the development of this study, the proposed diffusive model adjusted to the experimental data satisfactorily, thus making it possible to determine the effective coefficients of diffusion, whose results were consistent and compatible with those found in the current literature. Concerning the higher rates of evaporation and the lowest processing time, the best results were obtained in the drying of the unskinned, in natura tomatoes and of the skinned, pre-dehydrated tomatoes, at 60ºC, both processed in the convective drier. The results of the sensorial analysis of the unskinned and pre-treated product did not prove to be satisfactory. Regarding the shelf-live of the tomatoes, for a period of 45 days, no physicochemical or microbiological alteration of the product was noted

Desidratação de polpas de frutas pelo método foam-mat

This study aimed to investigate the foam mat drying process of pineapple and mango pulp, as well as to evaluate the final product quality. Initially, the selection of fruit and additives was conducted based on density and stability determinations of mango, seriguela, umbu and pineapple foams. After selecting pineapple and mango for further studies, the fruit pulps and fruit foams were characterized in regard to their physicochemical composition. The temperature (60oC or 70oC) and the foam thickness (4 and 11 mm) were evaluated in accordance to the obtained drying curves and after model adjustment. Mango and pineapple powders obtained at the best process conditions were characterized in regard to their physicochemical composition, solubility, reconstitution time. Yoghurts were prepared with the addition of pineapple and mango powders and they were evaluated for their sensory acceptance. Results show that the best drying rates were achieved by using 70o C and layers 4mm thick for both fruits. The Page model successfully fitted the drying experimental data and it can be used as a predictive model. Pineapple and mango powders showed acid pH, high soluble solids content, low water activity (approx. 0.25), lipids between 1.46% and 2.03%, protein around 2.00%, and ascorbic acid content of 17,73 mg/100g and 14.32 mg/100g, for mango and pineapple, respectively. It was observed higher ascorbic acid retention for pineapple and mango powders processed at 70o C, which would be explained by the lower drying time applied. The fruit powders exhibited high solubility and fast reconstitution in water. The sensory acceptance indexes for yoghurts with the addition of both fruit powders were higher than 70%, which reflect the satisfactory product acceptance

Estudo da desidratação osmótica da cenoura (Daucus carota) em fatias

In the area of food dehydration, drying of vegetables has a very representative position, it has the objective to preserve the surplus of crops and began with sun drying. Among the vegetable is the carrot, which had its origin in Southeast Asia and in Brazil is a vegetable cultivated enough. The principal objective of this works is to find alternative ways for the conservation of carrot slices by osmotic dehydration with additional drying in heart. Were initially defined the best conditions of pre-osmotic dehydration (temperature, immersion time, type of osmotic solution) based on the results of humidity loss, solid gain, weight reduction and efficiency ratio of predehydrated carrots slices. The osmotic solutions used were composed by NaCl (10%) and sucrose (50 ° Brix) named DO1 and sucrose (50 ° Brix) called DO2. Was made experiment of pre-osmotic dehydration of carrot slices in two temperature levels, with complementary drying in heart with air circulation at 70 º C. Sensory analysis was performed and the study of slices dehydration osmotically and the slices without osmotic treatment. The best results were obtained with the solution DO1 60°C with immersion time of 60 min. The drying of carrot slices presented period of constant rate and decreasing rate. The osmotic pre-treatment reduced the initial humidity of carrot slices, reducing the time to the product to reach the same humidity content. Fick's model, considering the shrinkage, and the Page s model, adapt satisfactorily to experimental datas, allowing the determination of effective diffusion coefficients, consistent with the references. The results of sensory analysis of dry product, showed greater acceptance of sliced carrots with osmotic treatment

Estudo do equilíbrio líquido-vapor do sistema água+etanol+líquido iônico visando a separação do álcool anidro

Anhydrous ethanol is used in chemical, pharmaceutical and fuel industries. However, current processes for obtaining it involve high cost, high energy demand and use of toxic and pollutant solvents. This problem occurs due to the formation of an azeotropic mixture of ethanol + water, which does not allow the complete separation by conventional methods such as simple distillation. As an alternative to currently used processes, this study proposes the use of ionic liquids as solvents in extractive distillation. These are organic salts which are liquids at low temperatures (under 373,15 K). They exhibit characteristics such as low volatility (almost zero/ low vapor ), thermal stability and low corrosiveness, which make them interesting for applications such as catalysts and as entrainers. In this work, experimental data for the vapor pressure of pure ethanol and water in the pressure range of 20 to 101 kPa were obtained as well as for vapor-liquid equilibrium (VLE) of the system ethanol + water at atmospheric pressure; and equilibrium data of ethanol + water + 2-HDEAA (2- hydroxydiethanolamine acetate) at strategic points in the diagram. The device used for these experiments was the Fischer ebulliometer, together with density measurements to determine phase compositions. The experimental data were consistent with literature data and presented thermodynamic consistency, thus the methodology was properly validated. The results were favorable, with the increase of ethanol concentration in the vapor phase, but the increase was not shown to be pronounced. The predictive model COSMO-SAC (COnductor-like Screening MOdels Segment Activity Coefficient) proposed by Lin & Sandler (2002) was studied for calculations to predict vapor-liquid equilibrium of systems ethanol + water + ionic liquids at atmospheric pressure. This is an alternative for predicting phase equilibrium, especially for substances of recent interest, such as ionic liquids. This is so because no experimental data nor any parameters of functional groups (as in the UNIFAC method) are needed

Palma forrageira (Opuntia ficus indica e Nopalea cochenillifera) como matéria-prima para produção de etanol celulósico e enzimas celulolíticas

The need for new sources of energy and the concern about the environment have pushed the search for renewable energy sources such as ethanol. The use of lignocellulosic biomass as substrate appears as an important alternative because of the abundance of this raw material and for it does not compete with food production. However, the process still meets difficulties of implementation, including the cost for production of enzymes that degrade cellulose to fermentable sugars. The aim of this study was to evaluate the behavior of the species of cactus pear Opuntia ficus indica and Nopalea cochenillifera, commonly found in northeastern Brazil, as raw materials for the production of: 1) cellulosic ethanol by simultaneous saccharification and fermentation (SSF) process, using two different strains of Saccharomyces cerevisiae (PE-2 and LNF CA-11), and 2) cellulolytic enzymes by semi-solid state fermentation (SSSF) using the filamentous fungus Penicillium chrysogenum. Before alcoholic fermentation process, the material was conditioned and pretreated by three different strategies: alkaline hydrogen peroxide, alkaline using NaOH and acid using H2SO4 followed by alkaline delignification with NaOH. Analysis of composition, crystallinity and enzymatic digestibility were carried out with the material before and after pretreatment. In addition, scanning electron microscopy images were used to compare qualitatively the material and observe the effects of pretreatments. An experimental design 2² with triplicate at the central point was used to evaluate the influence of temperature (30, 40 and 45 °C) and the initial charge of substrate (3, 4 and 5% cellulose) in the SSF process using the material obtained through the best condition and testing both strains of S. cerevisiae, one of them flocculent (LNF CA-11). For cellulase production, the filamentous fungus P. chrysogenum was tested with N. cochenillifera in the raw condition (without pretreatment) and pretrated hydrothermically, varying the pH of the fermentative medium (3, 5 and 7). The characterization of cactus pear resulted in 31.55% cellulose, 17.12% hemicellulose and 10.25% lignin for N. cochenillifera and 34.86% cellulose, 19.97% hemicellulose and 15.72% lignin for O. ficus indica. It has also been determined, to N. cochenillifera and O. ficus indica, the content of pectin (5.44% and 5.55% of calcium pectate, respectively), extractives (26.90% and 9.69%, respectively) and ashes (5.40% and 5.95%). Pretreatment using alkaline hydrogen peroxide resulted in the best cellulose recovery results (86.16% for N. cochenillifera and 93.59% for O. ficus indica) and delignification (48.79% and 23.84% for N. cochenillifera and O. ficus indica, respectively). This pretreatment was also the only one which did not increase the crystallinity index of the samples, in the case of O. ficus indica. However, when analyzing the enzymatic digestibility of cellulose, alkali pretreatment was the one which showed the best yields and therefore it was chosen for the tests in SSF. The experiments showed higher yield of conversion of cellulose to ethanol by PE-2 strain using the pretreated N. cochenillifera (93.81%) at 40 °C using 4% initial charge of cellulose. N. cochenillifera gave better yields than O. ficus indica and PE-2 strain showed better performance than CA-11. N. cochenillifera proved to be a substrate that can be used in the SSSF for enzymes production, reaching values of 1.00 U/g of CMCase and 0.85 FPU/g. The pretreatment was not effective to increase the enzymatic activity values

Estudo de uma coluna de absorção recheada para desidratação do gás natural utilizando microemulsão como absorvente

During natural gas processing, water removal is considered as a fundamental step in that combination of hydrocarbons and water favors the formation of hydrates. The gas produced in the Potiguar Basin (Brazil) presents high water content (approximately 15000 ppm) and its dehydration is achieved via absorption and adsorption operations. This process is carried out at the Gas Treatment Unit (GTU) in Guamaré (GMR), in the State of Rio Grande do Norte. However, it is a costly process, which does not provide satisfactory results when water contents as low as 0.5 ppm are required as the exit of the GTU. In view of this, microemulsions research is regarded as an alternative to natural gas dehydration activities. Microemulsions can be used as desiccant fluids because of their unique proprieties, namely solubilization enhancement, reduction in interfacial tensions and large interfacial area between continuous and dispersed phases. These are actually important parameters to ensure the efficiency of an absorption column. In this work, the formulation of the desiccant fluid was determined via phases diagram construction, employing there nonionic surfactants (RDG 60, UNTL L60 and AMD 60) and a nonpolar fluid provided by Petrobras GMR (Brazil) typically comprising low-molecular weight liquid hydrocarbons ( a solvent commonly know as aguarrás ). From the array of phases diagrams built, four representative formulations have been selected for providing better results: 30% RDG 60-70% aguarrás; 15% RDG 60-15% AMD 60-70% aguarrás, 30% UNTL L60-70% aguarrás, 15% UNTL L60-15% AMD 60-70% aguarrás. Since commercial natural gas is already processed, and therefore dehydrated, it was necessary to moister some sample prior to all assays. It was then allowed to cool down to 13ºC and interacted with wet 8-12 mesh 4A molecular sieve, thus enabling the generation of gas samples with water content (approximately 15000 ppm). The determination of the equilibrium curves was performed based on the dynamic method, which stagnated liquid phase and gas phase at a flow rate of 200 mL min-1. The hydrodynamic study was done with the aim of established the pressure drop and dynamic liquid hold-up. This investigation allowed are to set the working flow rates at 840 mL min-1 for the gas phase and 600 mLmin-1 for the liquid phase. The mass transfer study indicated that the system formed by UNTL L60- turpentine-natural gas the highest value of NUT

Análise energética de sistemas de produção de etanol de mandioca (Manihot esculenta Crantz)

This work aimed to analyze the energetic consumption of the etanol production system, using the cassava as carbohidrates source. The researches were carried out from the field in the mid region of Paranapanema river, São Paulo state, during the period January to December, 2007. The energy consumption referring to the phases of crop production and industrial processing were appraised. It was verified that the total energetic cost of the crop production corresponded to 9,528.33 MJ ha(-1), and the most onerous item was the inputs (35.72%). In the industrial step, the energetic consumption was equivalent to 2,208.28 MJ t(-1). The operations of hydrolysis/saccharification/treatment of the juice represented 56.72% of the total energetic expenditure. The cassava crop presented an energetic cost of 1.54 MJ L-1 in relation to the etanol produced in the main agronomic operations crop production, and 11.76 MJ L-1 in the industrial processing. The energy efficiency observed in the cultivation and industrialization of the cassava was of 1.76.

Avaliação energética da produção de etanol utilizando como matéria-prima a cana-de-açúcar

This research analyzed the energetic consumption of the etanol, using as raw-material sugar cane. The searches were carried out from the field in the Midle Paranapanema River Region, São Paulo state, in the period from January to December 2007. The referring energy consumption from the crop production phase and industrial processing were evaluated. It was verified that the total energetic cost of the crop production corresponded to 14370.9MJ ha(-1), and the most onerous item was the inputs (50.4%). In the industrial step, the energetic consumption was equivalent to 1,641.56MJ t(-1), The 'hydrolysis, saccharification and broth treatment operations' represented 71.72% of the total energetic expenditure. It was also observed an energetic cost of 2.0MJ L(-1) in relation to the etanol produced in the main crop production operations, and 19.4MJ L(-1) in the industrial processing. The energy efficiency observed in the crop production and industrialization were of 1.1.

Avaliação da concentração de pectinase no processo de hidrólise-sacarificação do farelo de mandioca para obtenção de etanol

Neste trabalho objetivou-se avaliar a concentração de pectinase (Pectinex Ultra SP-L) no processo de hidrólise-sacarificação do farelo de mandioca para produção de etanol. Foram avaliadas quatro concentrações da enzima pectinase com enzima complemetar as amilases e o tratamento com apenas as amilases. Realizou-se a caracterização do hidrolisado e resíduo fibroso resultantes do processo, e os resultados obtidos demonstraram que a concentração mínima de pectinase para um bom rendimento do processo foi 8Kg enzima/t fibras, com. 89,4% do amido hidrolisado. Quanto ao resíduo fibroso, este apresenta potencialidade de aproveitamento com base para produtos dietéticos ricos em fibras.

Efeitos de parâmetros de fermentação na produção de etanol a partir de resíduo líquido da industrialização da mandioca (manipueira)

Effect of fermentation parameters on ethanol production from cassava liquid residue (manipueira). "Manipueira", a liquid residue from the processing of cassava starch and flour, has recognized high pollution potential. Aiming at a possible use of "manipueira" as raw material for ethanol production, this study aimed to evaluate the effect of the percentage of inoculated yeast and fermentation temperature on the chromatographic profile of the components of wine of "manipueira". The residue was characterized for starch and sugar content, as well as pH and total acidity. The residue was hydrolyzed by the action of enzymes Termamyl 120 L and AMG 300 L. The hydrolysate obtained was fermented under different experimental conditions. A factorial central composite design (2(2)) with two independent variables and the response surface methodology were used to evaluate the results. The results showed a significant effect of variable parameters on the components of wine. The conditions of low fermentation temperature and lower percentages of inoculated yeast were the most appropriate to obtain ethanol from "manipueira".

Influência de pré-influência de pré-tratamentos sobre a desidratação osmótica de carambolas

A desidratação osmótica (DO) de fatias de carambola (Averrhoa carambola L.) em solução de sacarose foi estudada, com o objetivo de otimizar o processo. Num primeiro conjunto de experimentos, aplicou-se revestimento de coberturas comestíveis (pectina ou pectina+amido) sobre as fatias, seguido de do em solução aquosa de sacarose (50%, p/p, 27°C). Num segundo conjunto, foi realizada secagem parcial da cobertura, em estufa, antes da DO. Num terceiro conjunto de experimentos testou-se a adição de CaCl2 na solução osmótica. A aplicação dos revestimentos antes da do não melhorou a eficiência (máxima perda água/ganho soluto) devido à grande retenção de umidade e à fácil impregnação de sacarose nos mesmos, enquanto que o tecido vegetal sem revestimento restringiu mais o ganho de soluto e propiciou maior saída de água. A utilização de CaCl2 a 0,04M, na própria solução osmótica de sacarose, melhorou ligeiramente a eficiência do processo, em relação à solução sem o sal. A do em solução de sacarose, sem e com a adição de CaCl2, geraram resultados positivos na qualidade sensorial da carambola em fatias, desidratadas em secador (60 e 70°C), em comparação com a fruta não tratada, sendo que a melhor temperatura de secagem foi 60°C.

Reações de Etanol com CO/H2 na Presença do Sistema Catalítico Ru(acac)3/I-

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comportamento voltamétrico da redução de 2-furfuraldeído em etanol utilizando eletrodo de carbono vítreo

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