José Dalton Cruz Pessoa

Total anthocyanin content determination in intact açaí (Euterpe oleracea Mart.) and palmitero-juçara (Euterpe edulis Mart.) fruit using near infrared spectroscopy (NIR) and multivariate calibration.

The aim of this study was to evaluate near-infrared reflectance spectroscopy (NIR), and multivariate calibration potential as a rapid method to determinate anthocyanin content in intact fruit (açaí and palmitero-juçara). Several multivariate calibration techniques, including partial least squares (PLS), interval partial least squares, genetic algorithm, successive projections algorithm, and net analyte signal were compared and validated by establishing figures of merit. Suitable results were obtained with the PLS model (four latent variables and 5-point smoothing) with a detection limit of 6.2 g kg(-1), limit of quantification of 20.7 g kg(-1), accuracy estimated as root mean square error of prediction of 4.8 g kg(-1), mean selectivity of 0.79 g kg(-1), sensitivity of 5.04×10(-3) g kg(-1), precision of 27.8 g kg(-1), and signal-to-noise ratio of 1.04×10(-3) g kg(-1). These results suggest NIR spectroscopy and multivariate calibration can be effectively used to determine anthocyanin content in intact açaí and palmitero-juçara fruit.

Characterization of açaí (E. oleracea) fruits and its processing residues

The aim of this work was to study the source of the acai residue for its possible commercial applications by characterizing the fruit (fresh and dry mass), and performing an anatomic study of the pericarp from which were identified the origin of the anthocyanins, and fatty acids, and fibers; also the vascular system, its fibers constituents and fibrils were characterized. It was concluded that anthocyanins were located on the epiderm and external parenchyma, and that solids retained on the sieve come from the sclerenchyma, and that the fatty acids come from the storage parenchyma. The vascular tissue was formed by the fibers around 20 mm length. The length distribution of the fibrils had a mean length of 580µm.

Comportamento térmico e caracterização morfológica das fibras de mesocarpo e caroço do açaí (Euterpe oleracea Mart.)

The acai fruit agro industry produces a large amount of waste, mainly seeds and fibers, which is a serious environmental and public health problem. The aim of this work is to study the mesocarp fibers and the acai fruit seed to use in composite materials. The samples have been characterized by using thermogravimetric analysis (TGA/DTG) in inert and thermo-oxidative atmospheres, scanning electron and optical microscopy. The fibers have shown good stability until 230oC and a threedegradation step process in inert atmosphere. In oxidative atmosphere, the fibers presented a decrease in thermal stability and a change in the decomposition process from three to four steps. For the seeds, a similar behavior was observed, although a lower thermal stability was observed when compared to the fiber. Longitudinal morphology of the fibers that cover the acai seed is rough, and parenchyma cells can be seen on the surface. The acai fibers exhibited a thermal behavior comparable to other natural fibers used in composites, which is promising for new applications.

Apoplasm hydrostatic pressure on growth of cylindrical cells

According to the model frequently used as reference, plant cell growth occurs only when turgor surpasses a threshold. This model was proposed considering a cylindrical cell of constant wall thickness immerged in a water solution, with viscoelastic behaviour, hydraulic conductivity, variable extensibility, and unidirectional elongation. The author, Lockhart (1965), did not consider the effects of apoplasm hydrostatic potential, a subject treated later by Calbo and Pessoa (1994) who argued that this component of cell potential would interfere with cell growth rate. To evaluate this effect, where possible the same deductive procedures as those employed by Lockhart were used here, which resulted in a set of equivalent equations for cell growth, turgor and water potential, developed with respect to physico-chemical variables. Relationships were derived from the conductivity equation, the definition of extensibility, Hooks law, and considering that the tension on cell wall transversal section is proportional to turgor and apoplasm hydrostatic potential. The numeric solutions for the equations showed that suction increased extension rate at the beginning of cell growth. Some experiments on plant growth and structural models of cell walls are discussed to point out the role of suction on wall tensioning and cell hydration during cell elongation.

Avaliação da compressão em hortaliças e frutas e seu emprego na determinação do limite físico da altura da embalagem de comercialização

An estimate was made of the maximum tolerable height for piling boxes of fruit and horticultural products using ways of measuring the firmmess of the turgor of horticultural products. The flattening method and the firmometer generated similar results for tomato, potato, onion, carrot, chayote, bell pepper, yam, gilo, Peruvian carrot, radish, orange, apple, lemon, pear, grape, papaya, guava, plum and nectarine. Only the firmometer was able to measure the firmness of zucchini, kiwi, gherkin, cucumber, okra and green beans, because of the less regular surface. Firmness was measured in the equatorial part of these organs. It was assumed that 5% of the box base in contact with the flattened surface of the studied organs was the highest tolerated compression allowable during commercial use. To estimate the pile height that causes this deformation, the product weight and the usual impact acceleration, encountered during the transportation, were considered. This information along with specific product characteristics are being used to dimension a new box family, for palletized transport and commercialization of fruits and vegetables in Brazil.

Comparison of shape analysis methods for Guinardia citricarpa ascospore characterization

Among the diseases affecting the commercial citrus production, the citrus black spot (CBS) is considered to cause substantial losses. The analyses of particles in suspension in the orchards and collected into a disc have been applied as a preventive action trying to identify the presence of fungus spores before symptom appearance. In this paper, we show the results of several shape analysis methods applied to the fungus, the first step to the aimed computer aided vision system, capable to assist the identification process. Experiments and comparative results among the methods are presented in this paper, showing that better results were obtained applying the curvature method.

Development of a shelling method to recover whole kernels of the Cutia nut (Couepia edulis)

The kernel of the cutia nut (castanha-de-cutia, Couepia edulis (Prance) Prance) of the western Amazon, which is consumed by the local population, has traditionally been extracted from the nut with a machete, a dangerous procedure that only produces kernels cut in half. A shelling off machine prototype, which produces whole kernels without serious risks to its operator, is described and tested. The machine makes a circular cut in the central part of the fruit shell, perpendicular to its main axis. Three ways of conditioning the fruits before cutting were compared: (1) control; (2) oven drying immediately prior to cutting; (3) oven drying, followed by a 24-hour interval before cutting. The time needed to extract and separate the kernel from the endocarp and testa was measured. Treatment 3 produced the highest output: 63 kernels per hour, the highest percentage of whole kernels (90%), and the best kernel taste. Kernel extraction with treatment 3 required 50% less time than treatment 1, while treatment 2 needed 38% less time than treatment 1. The proportion of kernels attached to the testa was 93%, 47%, and 8% for treatments 1, 2, and 3, respectively, and was the main reason for extraction time differences.

Variação sazonal das trocas gasosas, turgescência relativa do tronco e produtividade em dois cultivares de seringueira em Votuporanga, SP, Brasil

RESUMO – (Variacao sazonal das trocas gasosas, turgescencia relativa do tronco e produtividade em dois cultivares de seringueira emVotuporanga, SP, Brasil). Alguns pesquisadores tem enfocado a influencia dos fatores agrometeorologicos e fisiologicos sobre a produtividadeda seringueira, mas a magnitude destas relacoes ainda nao e totalmente conhecida. Assim, no presente estudo, investigou-se a po ssivelrelacao entre alguns parâmetros fisiologicos e a producao de dois cultivares de seringueira, PB 235 e GT 1, cultivados em Votup oranga,Estado de Sao Paulo, durante o periodo seco e umido de 2000-2001. A producao total do periodo foi de 4.550,5 kg/ha, dos quais P B 235respondeu por 59,9%, com producao 12,6% maior que a de GT 1 no periodo seco e 29,8 % no periodo umido. Os valores da taxafotossintetica variaram entre 2,19 e 3,46 µmol m

Pressure measurement using thermal properties of materials

This work presents a design and two methods, one isothermal and one isovolumetric, for pressure measurements based on the compressibility coefficient (κ) and thermal expansibility (α) of the fluid under test. The setup and relevant construction details are described. To demonstrate the applicability of the isovolumetric measurement method, the setup was calibrated with respect to a Bourdon-type manometer; the other isothermic method was analyzed to determine construction details that could realize resolution requirements. The authors determined the effect of ambient temperature on device operation and the time response of the isovolumetric method. The device can be used to estimate the compressibility of a fluid and, in addition, could become an alternative for direct plant cell turgor measurement.

Caracterização morfomecânica para beneficiamento do fruto da castanha-de-cutia (Couepia edulis)

Cutia-Chesnut (Couepia edulis (Prance) Prance) is a fibrous fruit from western Amazon containing a tasteful almond that native peaple toast and mill to eat with cassava flour. The organoleptic characteritics of the almond make it a potential product for consumption at the cities in Brazil and abroad. Different from industries of oil extraction, the home consumer prefer and pay more for non-fragmented almonds. This is the first reason to develop an equipment to extract the almond from the fruit; the other reason is the lack of studies to develop methodologies of extraction for Cutia-Chesnut. This paper present part of the analisis recomended to the development of a methodology to extract the almond from the fruit: were avaliated qualitatively the rheological behaviour and mesocarp hidration; and measured the irregularities and sphericity of transversal section in respect to the perimeter of the fruit; the excentricity of transversal section in respect to its total area; and ocupation rate of the almond on transversal and longitudinal sections. These information will be used to develop an instrumentation to extract the almond, intact, from the fruit, with small operational risk and aplicable on forest and agroindustries.