Valter Arthur

Avaliação química, nutricional e fatores antinutricionais do feijão preto (Phaseolus vulgaris L.) irradiado

Mesmo o Brasil sendo o maior produtor de feijao, e necessario importar para suprir a grande demanda interna, que e agravada pelas grandes perdas por infestacoes durante o armazenamento. Para combater estas perdas o processo de irradiacao dos feijoes e uma alternativa. Foram avaliadas as alteracoes que ocorreram em graos de feijao preto crus e cozidos irradiados nas doses de 0, 2, 4, 6, 8 e 10kGy e avaliadas a quantidade de ferro, taninos e acido fitico, a digestibilidade da proteina e a disponibilidade de ferro. Para o teor de ferro em graos cozidos nao houve variacao (media de 118,17mg/Kg). Os teores encontrados de taninos para o cru nao variaram com a intensidade radioativa, nao sendo possivel deteccao nos cozidos. Quanto ao teor de acido fitico, ocorreu diminuicao da quantidade com aumento da irradiacao nos graos crus ate dose 8kGy. A digestibilidade da proteina diminuiu nos feijoes crus com o aumento da irradiacao. Ocorreu crescente aumento na disponibilidade de ferro nos feijoes crus irradiados (exceto na dose 8kGy), que nao varia das doses 4 e 6kGy. Os resultados encontrados neste trabalho mostram que o processo de irradiacao nao compromete o valor nutricional do feijao preto.Even so Brazil be producer of bean, it is necessay import to supply the itern demand which is very big. The damage to swarm over during the storage occur with frequency. To battle this damages the process of irradiation of beans is an option. The modifications was evaluated in black beans crude and cooked irradiated with dosis of 0, 2, 4, 6, 8 and 10kGy and evaluated the iron quantity, tannin and phitic acid, protein digestibity and iron availability. The iron content of cooked beans was not variation (mean 118.17mg/kg). The content of tannin for crude bean was not variation with the intensity of radiation. The phitic acid content decreased its quantity with irradiation dosis increase at crude beans until dosis 8kGy. The protein digestibility decreased with the increase of irradiation dosis in crude beans. Iron availability increased with the dosis of irradiaton (Except in dosis 8kGy) and was not variation of dosis 4 and 6kGy. The results demonstrated that the nutritional value was not engaged for irradiation process of black beans.

Diversidade de ácaros (Arachnida: Acari) em Coffea arabica L. cv. Mundo Novo, nos municípios de Jeriquara e Garça, Estado de São Paulo

The objective of this study was to characterize the diversity of mites on coffee plants of the Mundo Novo cultivar in two important coffee producing areas (Jeriquara and Garca) in the state of Sao Paulo. Samples of leaves, branches and fruits were fortnightly collected, from April 2001 to June 2003, from the middle third of 10 plants randomly taken from each field. Twelve leaves (each leaf from the third or forth pair from the distal part of each branch), 12 branches (apical 25 cm) and 100 fruits. A total of 13,052 specimens were collected in the two studied places, 7,155 in Jeriquara and 5,897 in Garca. From a total of 108 mite species collected from coffee plants in this study, forty five species were collected in both studied fields, which presented 56% of similarity. The number of species found exclusively in Jeriquara (47) was approximately three times higher than the number of species observed only in Garca (16). For Jeriquara, the diversity of mites on surface of leaves, as well as in domatia, and on branches and fruits was higher than for Garca. In both studied areas, Brevipalpus phoenicis (Geijskes, 1939) and Oligonychus ilicis (McGregor 1919) were the most abundant and frequent phytophagous mite species. Stigmaeids and phytoseiids were the most abundant and frequent predaceous mites in both localities. The most abundant and frequent predaceous species were Agistemus brasiliensis Matioli, Ueckermann & Oliveira, 2002, Zetzellia malvinae Matioli, Ueckermann & Oliveira, 2002, Euseius citrifolius Denmark & Muma, 1970, and Euseius concordis (Chant 1959) in Jeriquara; and Z. malvinae, E. citrifolius and E. concordis in Garca.

Efeito da irradiação gama nas características físico-químicas e sensoriais do arroz (Oryza sativa L.) e no desenvolvimento de Sitophilus oryzae L.

The objective of this research was to verify the viability of the gamma radiation as polished rice (Oryza sativa L.) conservation method. The samples were irradiated with doses of 0.5; 1.0; 3.0; and 5.0 kGy. Analysis of the grain breakage during the enriching process, longevity and reproduction of the Sitophilus oryzae L., centesimal composition, apparent amylose content, starch paste properties, color (instrumental), and the sensorial evaluation of raw and cooked rice were performed. It was verified that the irradiation did not change the percentage of grain breakage during the enrichment process, and it caused a negative effect on the development of insects. The irradiation did not change significantly the centesimal composition and the apparent amylase content. The Tukey test (p < 0.05) was conducted to verify the differences between the treatments. Gamma irradiation affected the pasting properties of the rice flour. Pasting parameters as temperature, peak, final viscosity, and setback values showed decreasing values with irradiation doses. Differences were detected in the sensorial aspect among the samples, and the sample irradiated with the dose of 1.0 kGy presented greater averages. Regarding the instrumental color parameter, it was observed the difference in the values b* indicating that the rice changed the white color for yellowish with the increase in the irradiation dose. The irradiation dose of 1.0 kGy proved the best to meet the objectives of this study.

Population dynamics of phytophagous and predaceous mites on coffee in Brazil, with emphasis on Brevipalpus phoenicis (Acari: Tenuipalpidae)

The objective of this work was to study the population dynamics of Brevipalpus phoenicis (Geijskes) and predaceous mites (Phytoseiidae and Stigmaeidae), as well as the interactions among these mite species, in a coffee plantation in the State of São Paulo, Brazil. Tydeids were also evaluated because of the high frequency of these mites on coffee plants. Samples of leaves, branches and fruits were taken fortnightly, from April 2001 to June 2003, from plants randomly chosen in the coffee plantation. B. phoenicis mites were found on leaves in higher number during the drier periods of the year. Among the predaceous mites, Euseius citrifolius Denmark & Muma and Euseius concordis (Chant) were the most frequent species on the surface of leaves. During the evaluations, 72,534 domatia were cut and opened to remove the mites, from 6,360 leaves examined. Zetzellia malvinae Matioli, Ueckermann & Oliveira was the most frequent predator species found inside domatia. Significant correlations were observed between population dynamics of, among others, E. concordis and B. phoenicis, Z. malvinae and B. phoenicis, and Z. malvinae and E. concordis. Significant correlations were also verified between the number of domatia and the population densities of B. phoenicis, E. concordis, Lorryia sp. and Z. malvinae. Interactions between predator–prey and predator–predator on coffee plants are discussed. The influence of the meteorological factors temperature and precipitation on the most frequent mite species is also discussed.

Chlorfenapyr resistance in the spider mite Tetranychus urticae: stability, cross-resistance and monitoring of resistance

The two-spotted spider mite, Tetranychus urticae Koch, is a key pest of many agricultural crops. Studies of stability of resistance, cross-resistance relationships and monitoring of chlorfenapyr resistance were carried out with T. urticae to provide basic information necessary to define effective acaricide resistance management strategies for this pest. Chlorfenapyr resistance was shown to be stable in the absence of selection pressure under laboratory conditions. The activities of seven different acaricides against chlorfenapyr-resistant and -susceptible strains of T. urticae were evaluated. The results indicated possible positive cross-resistance between chlorfenapyr and the acaricides abamectin, propargite and etoxazole. No cross-resistance was detected for the acaricides milbemectin, fenpyroximate and diafenthiuron. A possible negatively correlated cross-resistance was observed between chlorfenapyr and spiromesifen. The evaluation of 21 T. urticae populations from several crops in the States of São Paulo, Mato Grosso, Goiás, and Bahia, in Brazil, indicated that the susceptibility of mites to chlorfenapyr was variable, with percentages of resistant mites ranging from 0.0 to 86.5%. The highest resistance frequencies were observed in ornamental plants in the State of São Paulo. Some populations from cotton and papaya also presented high frequencies of chlorfenapyr resistance. This is the first report on chlorfenapyr resistance in T. urticae on cotton and papaya in Brazil. Strategies for the management of acaricide resistance are discussed.

Alterações físico-químicas em morangos (Fragaria anassa Duch.) irradiados e armazenados

Strawberries have a short postharvest life due to the rapid spoilage caused by fungal infections, even when stored under refrigeration. The present research had the objective of evaluating the physical and chemical alterations in irradiated strawberries. Strawberries (Fragaria anassa Duch.) of the Sweet Charles variety, harvested in the region of Valinhos-SP, Brazil, were irradiated one day after harvest with a source of 60Co in the doses of 0.5; 1.0; 1.5 and 2.0 kGy and control, stored under refrigeration (4 °C) for 1, 8, 15, 22 and 29 days. The control sample was not submitted to irradiation. For the characterization of the fruits, the chemical composition was determined. The fruits were evaluated as to total soluble solid content (°Brix), total titrimetric acidity, pH and total and soluble pectin at the different time periods. Irradiation did not cause alterations in any of the parameters analyzed between irradiated samples and the control, but the periods of storage were responsible for the differences observed in all the parameters. It was concluded that the irradiation process did not change the amount of pectin, soluble solid content (°Brix), total titrimetric acidity and pH, but storage time had an influence on these parameters.

Efeitos da radiação gama na cor, capacidade antioxidante e perfil de ácidos graxos em amendoim (Arachis hypogaea L.)

Irradiation is efficient at extincting fungi contamination in peanuts. Peanuts have high biologic value protein, minerals, vitamin E, complex B, and high concentration of lipids. The objective of this research is to evaluate the gamma irradiation effect on color, total phenolic, antioxidant activity, and fatty acid profile in peanuts ( Arachis hypogaea L.). Cultivars IAC-Tatu ST and IAC-Runner 886 were submitted to gamma radiation with doses of 5.0; 7.5; 10.0, and 15.0 kGy and storage at room temperature. There was no significant difference in the color of IAC-Tatu ST. However, significant difference was found in the luminosity and Chroma in IAC-Runner 886. Total fenolics differed from the control with 33.27 mg.g -1 and treatment dose of 10.0 kGy with 58.60 mg.g -1 in IAC-Tatu ST. This parameter not had significant difference in IAC-Runner 886 and the control with 51.59 mg.g -1 . The antioxidant activity did not present significant difference with a dose of 10.0 kGy, recommended for the elimination of fungi in peanuts. The dose of 10.0 kGy showed a decrease in saturated fatty acids, increase in unsaturated fatty acids, and an increase in linolleic acid. The oleic/linoleic relation decreased justifying further research correlating storage and oxidative stability.

Alterações químicas e nutricionais do grão-de-bico (Cicer arietinum L.) cru irradiado e submetido à cocção

SUMMARY NUTRITIONAL AND CHEMICAL ALTERATION OF RAW, IRRADIATED AND COOKED CHICKPEA (Cicer arietinum L.). The work objective was analyzing, in chickpea seeds not irradiated, the centesimal and mineral composition to verifying the alterations on the nutritional characteristics caused by the cooking process. Also were carried out analysis of the iron availability in vitro, protein digestibility in vitro and the profile of amino acids in the raw and cooked in the control and irradiated seeds (doses of 2, 4, 6, 8 and 10 kGy). The results of the mineral analysis showed that only phosphorus decrease significantly (p≤0.05) with cooking process. At the centesimal composition, ash and carbohydrates available decreased significantly (p≤0,05). In the control and in the doses of 4 and 6 kGy the cooking hasn’t influenced the digestibility of the protein, but the treatments that received radiation doses of 2, 8 and 10 kGy were influenced. The cooked chickpea has shown better digestibility in higher doses of radiation although the treatments have shown low digestibility. The raw chickpea presented a better dialysis of iron in the control and in the doses 2 and 4 kGy and the cooked chickpea presented improvement according to the increase of radiation doses. In relation to essential amino acids, chickpea has presented an adequate nutritional value, except for methionine.

Efeito da radiação gama e do armazenamento na qualidade de padúnculos de caju (Anacardium occidentale L.)

Devido a altas perdas de pedunculos de caju, metodos de conservacao sao necessarios para um maior aproveitamento dos mesmos. Com esse objetivo, pedunculos de caju vermelho, maduros, obtidos de cajueiro anao precoce, foram irradiados com doses de 0, 0,5 e 1,0 kGy e armazenados por 9 dias, refrigerados 4 oC para verificacao da estabilidade da qualidade durante o periodo de armazenamento. Para isso foram realizadas analises quimicas, verificando mudancas nos teores de acucares redutores, Brix, vitamina C e pH. Alteracoes na firmeza e cor tambem foram observadas. Os teores de vitamina C diminuiram tanto em funcao do tempo de estocagem como em funcao das doses de radiacao empregadas. A firmeza dos frutos foi influenciada tanto pelas diferentes doses de radiacao quanto pelo armazenamento, aumentando durante o armazenamento e diminuindo quanto maiores as doses de irradiacao. O metodo de conservacao por irradiacao mostrou-se eficiente para o prolongamento da vida de prateleira dos pedunculos de caju e manutencao de sua qualidade pos-colheita.

Gamma ionization of Phagicola longa (Trematoda:Heterophyidae) in Mugilidae (pisces) in São Paulo, Brazil

Abstract The mullet (Mugilidae) is a fish caught in large quantities in brackish and marine waters of the southern Brazilian coast, which in consequence of its raw consumption as “sashimi”, a typical Japanese dish, has led to ten cases of human infection by Phagicola longa in Sao Paulo, Brazil. The mullet acts as a second intermediate host for the parasite, as in human heterophysiasis in the Near and Far East. In order to control these infections under commercial storage conditions and in raw consumption, the radiolysis of P. longa was studied in three mullet species-the silver mullet (Mugil curema), the grey mullet (M. platanus) and the “paratipema” (Mugil sp.) - subjected to ionization ranging from 1.0 to 10.0 kGy (2.21 kGy/h). It was observed that 1.0 and 2.0 kGy caused a motility decrease in silver mullet parasites from 100% to 15% and 17%, and that doses of 4.0 and 10.0 kGy caused metacercaria inviability. The parasite motility decreased in the grey mullet treated with doses of 2.0, 2.5, 3.0 and 3.5 kGy, from 56% to 31%, 9%, 18% and 5%, respectively, 4.0 kGy tending to be the control dose for P. longa. This dose also controls other metacercaria found in the “parati-pema”, without changing the odor, color or appearance of the treated mullet.