Rossana Maria Feitosa de Figueirêdo

Caracterização físico-química de méis produzidos no Estado do Piauí para diferentes floradas

The objective of this work was to evaluate the physical-chemical composition of honeys produced in the Piaui State, located in semi-arid region of Northeast Brazil. The honeys produced from marmeleiro (Croton sonderianus Mull. Arg.), jitirana (Hyptis suaveolens), camaratuba (Cratylia mollis Mart. ex Benth), silvestre (Serjania glabrata) and angico de bezerro (Piptadenia moniliformis), were analysed following the methods recommended by the Brazilian Ministry of Agriculture and Normative Instruction of October 2000. the following analyses were performed: moisture, hydroxymethylfurfural (HMF), reducing sugars, apparent sucrose, ash, free acidity, insoluble solids in water, diastatic activity, oBrix and pH. The individual values of each analyzed parameter were compared with the standards established by Ministry of Agriculture and Suplies and presented satisfactory results, matching the standards cited by the Normative Instruction.

Armazenamento da polpa de acerola em pó a temperatura ambiente

This work had for objective, to study the storage of the pulp of powdered West Indian cherry wrapped in sacks of polyethylene for 60 days, under atmosphere it adapts. The West indian cherry powder was obtained by the drying of a solution containing 90% of West Indian cherry pulp and 10% of maltodextrin, in a dryer of the type spouted bed, with temperature of the air of drying of 70oC. Every 10 days were made evaluations of the parameters ascorbic acid, humidity, pH and color. The results a decrease in the tenor of ascorbic acid of 29.72%; an increase of 51.31% in the humidity; the value of the pH stayed practically unaffected oscillating between 3.7 and 3.8 units of pH and it was observed alterations in the color of the West Indian cherry powder at the end of the storage, with increment in the values of the intensity of red and yellow and decrease of the brightness

Microbiologia de farinhas de mandioca (Manihot esculenta Crantz) durante o armazenamento

This work was accomplished with the aim of evaluating the microbiological characteristic in cassava flours (Manihot esculenta Crantz) simple and temperate, stored during 180 days. The materials consisted of five samples, being one of cassava flour without mixture (simple) and the others of temperate cassava flours. The simple flour was packed in polyethylen bags of low density with capacity of 1,0kg and the temperate flours were packed in colored polipropilen bags, with capacity of 0.5kg. In all the samples fecal coliformes, Staphylococcus aureus, mesophile bacterias, yeasts counting and Salmonella sp research were accomplished. The analyses were accomplished in intervals of 30 days. Differences were not detected among the microbiological characteristic of the simple samples and the temperate ones. The storage didnx92t affect the microbiological standard of the samples. The samples presented sterility for fecal coliformes, Salmonella sp. and Staphylococcus aureus. The values found for fecal coliformes, Salmonella sp., Staphylococcus aureus, mesophile bacterias and yeasts were inside the patterns fastened by the Brazilian legislation.

Caracterização termofísica de polpas de bacuri

SUMMARY THERMOPHYSICAL CHARACTERIZATION OF BACURI PULP. Thermophysical properties, specific heat, density, thermal diffusivity and thermal conductivity of bacuri pulps at different concentrations were studied. The specific heat was determined by the mixture calorimeter method; the density was determined by the pycnometer; the thermal diffusivity was obtained by using the infinite cylinder method; the thermal conductivity was determined from the experimental results obtained for density, specific heat and thermal diffusivity. All the properties were also theoretically determined using proposals equations and regressions. Among the experimental results the specific heat varied from 3.616 to 2.986 kJ/kgoC; the density varied from 1,008.40 to 1,048.36 kg/m 3 ; the thermal diffusivity varied between 1.637x10-7 and 1.787x10-7 m2/s; the thermal conductivity varied from 0.50 to 0.64 W/moC. Except for the density, the value of all the properties decreased, whereas the concentration increased. The thermal conductivity was fitted

Avaliação sensorial e da atividade de água em farinhas de mandioca temperadas

Este trabalho foi realizado com o objetivo de avaliar sensorialmente quatro amostras de farinhas de mandioca temperadas e verificar o comportamento da atividade de agua ao longo de um periodo de cento e oitenta dias de armazenamento. As farinhas consistiram de cinco amostras, sendo uma de farinha de mandioca seca embalada em sacos plasticos de polietileno de baixa densidade, capacidade 1.000 g e quatro de farinhas de mandioca temperadas, obtidas a partir da primeira, embaladas em sacos plasticos de polipropileno pigmentado, capacidade 500 g, tendo sido utilizada como embalagem secundaria sacos de polietileno de baixa densidade, capacidade 10.000 g. A analise quanto a atividade de agua foi realizada logo apos o processamento e durante todo o periodo de armazenamento, com intervalos de trinta dias. Com relacao a analise sensorial as amostras obtiveram aceitacao acima de 5,5 pontos, superando o valor intermediario da escala hedonica. A atividade de agua aumentou com a temperatura e com o tempo de armazenamento, porem, com valores inferiores a 0,6.

Comportamento reológico e efeito da temperatura da polpa de pequi em diferentes concentrações

Despite the high economic potential of pequi pulp, studies related to its physical properties for use in industrial projects and processes are still scarce. Therefore, this study aimed to assess the rheological behavior of pequi pulp with different total soluble solids contents (6, 8, 10 and 12 °Brix) and at different temperatures (25, 30, 35, 40, 45 and 50 °C). The experimental measurements were made using a Brookfield viscometer and the rheological models Ostwald-de-Waelle, Herschel-Bulkley and Mizrahi-Berk were fitted to the experimental data for shear stress and shear rate. Of the rheological models tested, the best fits were observed using the Mizrahi-Berk model. The pequi pulp showed a trend for decreasing apparent viscosity with increasing shear rate, behaving as a non-Newtonian fluid with pseudoplastic characteristics.

CHARACTERIZATION OF RIPENING STAGES OF MYRTLE FRUIT

The myrtle (Eugenia gracillima Kiaersk.) is a native fruit species in the Chapada of Araripe, state of Pernambuco, Brazil. The fruits are collected from the wild and are consumed fresh or processed as pulp, juice, jelly, liquor or desserts. Myrtle fruit production is of significant socioeconomic value for the region and, therefore, the description of myrtle fruit ripening stages may contribute to the development of its production chain. As a result, the objective of the present study was to evaluate the physical, quality and ripening changes of myrtle fruits at different developmental stages. The fruits were picked at five distinctive stages and evaluated for longitudinal and transverse diameters; fresh, dry and water mass; water contents; soluble solids (SS); titratable acidity (TA); pH; SS/TA ratio; carbohydrates (starch, total, reducing and nonreducing sugars); ascorbic acid; total pectin, soluble pectins and percentage of pectin solubilization; polymeric, oligomeric and dimeric phenolics; total anthocyanins, carotenoids and chlorophyll; and yellow flavonoids. Along fruit ripening processes increases in SS, anthocyanins and carotenoids, in the SS/TA ratio and of percentages of pectin solubilization were determined. On the other hand, decreases in TA and total chlorophyll were observed. The ripening stage at which peel color is completely dark red (ripening stage 4) is most appropriate to harvest myrtle fruits for human consumption.

CINÉTICA DE SECAGEM EM CAMADA DE ESPUMA DA POLPA DE MANGA CV. KEITT

This study aimed to assess the foam-mat drying kinetics of mango pulp (cv. Keitt) adding 1% Emustab® and 1% Super Liga Neutra®, for a whipping time of 20 minutes, dried in a forced-air convection oven at different temperatures (50, 60 and 70C) and foam layer thicknesses (0.5, 1.0 and 1.5 cm). Drying kinetic data were used to build drying curves and then fit to Page, Henderson, Henderson and Pabis, Logarithmic and two-term Exponential models. Both temperature and foam layer thickness influenced drying time, which reached the shortest value at the highest temperature and smallest thickness. The Page model provided the best fit to the experimental drying curve data.

Comportamento reológico das polpas de noni integral e concentradas

The rheological behaviour of fruit pulps allows one to obtain important information about their flow under distinct conditions and at different stages of the process. Thus the present study aimed to analyse the rheological behaviour of whole noni pulp (Morinda citrifolia L.) and that concentrated to 30 and 50 °Brix. The rheological parameters determined were: shear stress, strain rate and apparent viscosity, using a Brookfield viscometer at rotational speeds of 5 to 200 rpm and temperatures from 5 to 65 °C. Of the models tested, the Mizrahi & Berk model best represented the rheograms of the whole and concentrated noni pulps with the following fittings: R2 ≥ 0.8219, X2 ≤ 0.1569 and P ≤ 2.26%. The pulps studied presented values u200bu200bfor the fluid behaviour index of less than one (n<1), characterizing them as non-Newtonian fluids with pseudoplastic behaviour. The Arrhenius equation can be used to demonstrate the effect of temperature on the apparent viscosity for the whole and 30 oBrix pulps at all speeds, and for the pulp with 50°Brix preferably at rotational speeds of 5, 10 and 20 rpm.

One-dimensional numerical solution of the diffusion equation to describe wood drying: comparison with two- and three-dimensional solutions

This article describes drying of wood cut into parallelepiped shaped pieces. A one-dimensional numerical solution of the diffusion equation with boundary condition of the third kind was proposed to describe the process. The lumber was cut into the following dimensions: thickness Txa0=xa036xa0mm, height Hxa0=xa0100xa0mm and length Lxa0=xa0745xa0mm. The convective drying experiment was carried out with forced air at temperature of 40xa0°C, relative humidity of 40xa0% and velocity of 3xa0mxa0s−1. An optimizer was coupled with the proposed numerical solution to determine the process parameters. Comparison of the results obtained in this article (one-dimensional) with results from the literature (two- and three-dimensional) indicated good agreement between the process parameters (and also simulations). However, the optimization time for one-dimensional model is about 15 times less than the optimization time for the two-dimensional case.