RESUMO

A vida-de-prateleira pode ser definida como um período de armazenamento em que produtos com alta qualidade inicial permanecem adequados para consumo. Para sua determinação, várias amostras devem ser submetidas a uma série de testes e examinadas durante um período de tempo até o limite de aceitação. O objetivo deste trabalho foi avaliar a qualidade química e sensorial de mamões minimamente processados, submetidos aos tratamentos com e sem sementes, mantidos sob refrigeração. Os frutos de mamão (Carica papaya L.) cultivar Havaí foram adquiridos na CEASAMINAS-Uberlândia com as seguintes dimensões 115,7 a 119 mm de comprimento por 63 a 64,7 mm de calibre. Estes foram sanitizados com hipoclorito de sódio a 200 ppm, durante 12 minutos e logo após foram realizados cortes longitudinais uniformes. Foram feitas análises físico-químicas e sensoriais nos tempos 1, 6, 8, 13 e 15 dias de armazenamento nas condições de 12,57°C ± 1,04°C e 81,5% ± 4,8% UR. O experimento apresentou um delineamento inteiramente casualisado em esquema fatorial (2 x 5), sendo com e sem semente e 5 períodos de avaliação com 6 repetições. Os resultados mostraram que os sólidos solúveis totais, pH e acidez total titulável não apresentaram diferenças estatisticamente significativas no teste de F (p<0,05) durante os 15 dias de armazenamento. A avaliação sensorial indicou que houve desidratação parcial das sementes observados no tratamento com semente e do endocarpo para o tratamento sem semente no 6 dia de armazenamento. Pelas analises realizadas, a presença de sementes em Carica papaya L. cultivar Havaí, minimamente processado,melhora as características sensoriais dos frutos contribuindo para maior tempo de vida de prateleira.(AU)

The shelf life may be defined as a period of storage in that products with high initial quality keep proper characteristics to consume. To its determination, several samples must be submitted to a number of tests and evaluated for a period up to the acceptation limit. The goal of this work was to evaluate the chemical and sensory quality of fresh cut papaya, submitted to treatments with or without seeds and kept under refrigeration. Papaya fruits cultivar Havai were got at CEASAMINAS - Uberlândia, Brazil with the following dimensions: 115.7 to 119 mm of length and 63 to 64.7mm of calibration. The fruits were sanitized with sodium hypochloride at 200 ppm for 12 minutes and cut longitudinally. Physical-chemical and sensory analyses were carried out at 1, 6, 8, 13 and 15 days of storage at 12,57ºC ± 1,04ºC and 81,5% ± 4,8% RH. The experiment was carried out in a completely randomly design in factorial 2x5, corresponding to slices with or without seed and 5 periods of evaluation, with 6 replicates. Soluble solids, pH and titratable acidity did not show differences statistically significant for the F test (p<0.05) during 15 days of storage. The sensory evaluation showed that there was partial dehydration of seed observed intreatment with seed and of the endocarp to the treatment without seed, at 6th day of storage. The endocarp showed appearance more dry, with visible loss of the characteristic color in the treatment without seed in comparison to treatment with seed. Considering the analysis carried out, it may be concluded that the presence of seeds in fresh cut papaya Havai improve the sensory characteristics of thefruits and increase their shelf life. (AU)

Assuntos

RESUMO

A vida-de-prateleira pode ser definida como um período de armazenamento em que produtos com alta qualidade inicial permanecem adequados para consumo. Para sua determinação, várias amostras devem ser submetidas a uma série de testes e examinadas durante um período de tempo até o limite de aceitação. O objetivo deste trabalho foi avaliar a qualidade química e sensorial de mamões minimamente processados, submetidos aos tratamentos com e sem sementes, mantidos sob refrigeração.(...)Os resultados mostraram que os sólidos solúveis totais, pH e acidez total titulável não apresentaram diferenças estatisticamente significativas no teste de F (p<0,05) durante os 15 dias de armazenamento. A avaliação sensorial indicou que houve desidratação parcial das sementes observados no tratamento com semente e do endocarpo para o tratamento sem semente no 6 dia de armazenamento. (...) Pelas analises realizadas, a presença de sementes em Carica papaya L. cultivar Havaí, minimamente processado,melhora as características sensoriais dos frutos contribuindo para maior tempo de vida de prateleira.

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RESUMO

In the present study, five analogous herbicides, namely Imazapyr (IMZR), Imazapic (IMZC), Imazethapyr (IMZT), Imazamox (IMZX) and Imazaquin (IMZQ), were evaluated for genotoxicity (mutagenic and recombinagenic activity) in the wing somatic mutation and recombination test (SMART) of Drosophila melanogaster. They are classified as imidazolinone (IMI) herbicides and their mode of action is to inhibit acetohydroxyacid synthase (AHAS), an enzyme involved in the biosynthesis of the amino acids leucine, isoleucine and valine. Two crosses were used: the standard (ST) cross and the high bioactivation (HB) cross. The latter is characterized by high levels of cytochrome P450 conferring increased sensitivity to promutagens and procarcinogens. Three-day-old larvae were exposed by chronic feeding (48 h) to four different concentrations of these herbicides (2.5, 5.0, 10.0 or 20.0 mM). For the evaluation of genotoxic effects, the frequencies of spots per individual in the treated series were compared to the concurrent negative control series (ultrapure water). Imazapyr, Imazapic and Imazethapyr gave negative results with both crosses of the wing spot test. In the ST cross, Imazamox showed positive results only for large single spots (20.0 mM IMZX) and weak positive results for total spots (10.0 and 20.0 mM IMZX), while Imazaquin showed positive results only for large single spots (5.0 and 20.0mM IMZQ) and a weak positive result for total spots (20.0 mM IMZQ). These positive results are mainly due to induced recombination and to a minor extent to mutations. In the HB cross, only Imazamox (5.0 mM IMZX) showed a weak positive result for small single spots. The positive control urethane, a promutagen, caused an increase in the number of all types of spots in both crosses. In conclusion, the results of chronic treatments performed at high doses (toxicity was observed at higher doses) shows the existence of a genotoxic risk for IMZX and IMZQ exposure under these experimental conditions, and indicate the need for further research to delineate the exact mechanisms involved.

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RESUMO

In this study two different crosses involving the wing cell markers mwh and flr³ (standard (ST) cross and high bioactivation (HB) cross, the latter being characterized by a high constitutive level of cytochrome P450 which leads to an increased sensitivity to a number of promutagens and procarcinogens) were used to investigate the modulatory effects of ascorbic acid (AA) combined with the antitumor agent doxorubicin (DXR) in Drosophila melanogaster. We observed that the two different concentrations of AA (50 or 100 mM) had no effect on spots frequencies, while DXR treatments (0.2 or 0.4 mM) gave positive results for all types of spots, when compared to negative control. For marker-heterozygous (MH) flies, a protective effect was observed with the lower concentration of AA (50 mM) that was able to statistically decrease the frequency of spots induced by DXR (0.2 mM), while an enhanced frequency of spots induced by DXR was observed with the higher concentration of AA (100 mM), when compared to DXR treatment (p < 0.05). These results suggest that AA may interfere with free radicals generated by DXR and with other possible reactive metabolites. The efficiency of AA in protecting the somatic cells of D. melanogaster against mutation and recombination induced by DXR is dependent on the dose used and the protection is directly related to the activity of cytochrome P450 enzymes.

RESUMO

The Drosophila melanogaster somatic mutation and recombination test (SMART) was used to assess the genotoxicity of surface (S) and bottom (B) water and sediment samples collected from Sites 1 and 2 on the Japaratuba River (Sergipe, Brazil), an area impacted by a petrochemical industrial complex that indirectly discharges treated effluent (produced water) into the river. The genotoxicity tests were performed in standard (ST) cross and high bioactivation (HB) cross flies and were conducted on samples taken in March (dry season) and in July (rainy season) of 2003. Mutant spot frequencies found in treatments with unprocessed water and sediment samples from the test sites were compared with the frequencies observed for similar samples taken from a clean reference site (the Jacarecica River in Sergipe, Brazil) and those of negative (ultrapure water) controls. While samples from the Japaratuba River generally produced greater responses than those from the Jacarecica River, positive responses were detected for both the test and reference site samples. All the water samples collected in March 2003 were genotoxic. In July 2003, the positive responses were restricted to water samples collected from Sites 1 B and 2 S in the ST cross. The genotoxicity of the water samples was due to mitotic recombination, and the samples produced similar genotoxic responses in ST and HB flies. The spot frequencies found in the July water samples were considerably lower than those for the March water samples, suggesting a seasonal effect. The only sediment samples that were genotoxic were from Site 1 (March and July) and from the Jacarecica River (March). The genotoxins in these samples produced both somatic mutation (limited to the Site 1 sample in HB flies) and recombination. The results of this study indicate that samples from both the Japaratuba and Jacarecica Rivers were genotoxic, with the most consistently positive responses detected with Site 1 samples, the site closest to the putative pollution source.

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