93 resultados para Arafura Shelf
Resumo:
The objective of this work was to evaluate the effect of growth regulators on gas diffusion and on metabolism of 'Brookfield' apple, and to determine their correlation with quality characteristics of fruit stored in controlled atmosphere. A completely randomized design was used with four replicates. After eight months of storage, the effects of water (control), aminoethoxyvinylglycine (AVG), AVG + ethephon, AVG + naphthaleneacetic acid (NAA), ethephon + NAA, sole NAA, 1-MCP, ethylene absorption by potassium permanganate (ABS), AVG + ABS, and of AVG + 1-MCP - applied at different rates and periods - were evaluated on: gas diffusion rate, ethylene production, respiratory rate, internal ethylene concentration, internal CO2 content, mealiness, and intercellular space. Fruit from the control and sole NAA treatments had the highest mealiness occurrence. Growth regulators significantly changed the gaseous diffusion through the pulp of 'Brookfield' apple, mainly in the treatment AVG + ABS, which kept the highest gas diffusion rate. NAA spraying in the field, with or without another growth regulator, increased ripening metabolism by rising ethylene production and respiration rate, and reduced gas diffusion during shelf life. AVG spraying cannot avoid the ethephon effect during the ripening process, and reduces both the internal space and mealiness incidence, but it is not able to induce ethylene production or to increase respiration rates.
Resumo:
Abstract: The objective of this work was to define procedures to assess the tolerance of cassava genotypes to postharvest physiological deterioration (PPD) and to microbial deterioration (MD). Roots of six cassava genotypes were evaluated in two experiments, during storage under different environmental conditions: high temperature and low soil moisture; or low temperature and high soil moisture. Roots were treated or not with fungicide (carbendazim) before storage. Genotype reactions to MD and PPD were evaluated at 0, 2, 5, 10, 15, 20, and 30 days after harvest (DAH), in the proximal, medial, and distal parts of the roots. A diagrammatic scale was proposed to evaluate nonperipheral symptoms of PPD. Fungicide treatment and root position did not influence PPD expression; however, all factors had significant effect on MD severity. Genotypes differed as to their tolerance to PPD and MD. Both deterioration types were more pronounced during periods of higher humidity and lower temperatures. The fungicide treatment increased root shelf life by reducing MD severity up to 10 DAH. Whole roots showed low MD severity and high PPD expression up to 10 DAH, which enabled the assessment of PPD without significant interference of MD symptoms during this period.
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Abstract:The objective of this work was to develop a scale to assess the severity of postharvest physiological deterioration (PPD) of cassava roots, and to validate this scale for accuracy and reproducibility estimates. A diagrammatic scale (0 to 100%) for the damaged roots was analyzed according to precision, accuracy, and reproducibility. Seven evaluators (four with experience and three without it) quantified the PPD severity, with or without the scale, considering 150 roots with different levels of PPD. Without and with the use of the scale, respectively, the inexperienced evaluators obtained coefficients of determination (R2) from 0.76 to 0.86 and 0.87 to 0.92, and the experienced evaluators obtained R2 from 0.90 to 0.96 and 0.96 to 0.97. The values of the intercept (a) obtained by both the experienced and inexperienced evaluators who did not use the scale were all significant, while after using the scale, only two evaluators got values that were not significantly different from one. Evaluation reproducibility between the evaluators ranged from 0.61 to 0.91 for the inexperienced ones and from 0.83 to 0.95 for the experienced ones. The proposed diagrammatic scale was considered appropriate to estimate the severity of PPD in cassava roots, and can be used to identify sources of tolerance to postharvest deterioration.
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Effects of refrigerated storage and different packages on postharvest behaviour of fruits of atemoya (Annona cherimola x A. squamosa) cv. PR3 were investigated. Fruits were individually sealed in copolymer (PD-955) and low-density polyethylene (LDPE) bags and stored for 21 days at 15°C or 25°C. Then they were unwrapped and maintained at 25°C, for ripening. Weight loss and firmness of fruits were both affected by storage time, temperature and packaging. Weight loss in packaged atemoyas was lower than in the control, non-wrapped fruits. A non-trained panel scored the atemoyas for overall eating quality and appearance. Fruits sealed in LDPE did not ripen, probably due to an injurious atmosphere developed inside the package. Atemoyas packaged in PD-955 film had a shelf-life of 17 days against 13 days of the control ones, both stored at 15°C, an increase of 30% on shelf-life.
Resumo:
The objective of this work was to compare the effects of four different concentrations of cassava starch film and storage temperature on shelf life and the quality of a genotype of acerola from the Germplasm Active Bank (GAB) of Federal Rural University of Pernambuco, Brazil. Sound orange-reddish acerola fruits were washed with a chlorine solution (100 mg.L-1 active chlorine) and randomly distributed into different lots. The fruits were dipped for 3 min in a cassava starch suspension with concentrations of 1, 2, 3 and 4% (w/v) and the control without coating, stored at 10ºC (85% RH) and 22ºC (85% RH). The total soluble solids (TSS), pH, titratable acidity (TA) and ascorbic acid (AA) were determined at harvest and regular interval during storage. The use of cassava biofilm at 1% on acerola fruits maintained the highest ascorbic acid content and the temperature of 10ºC extended storage life. The fruits coated with 1 and 2% biofilm could be stored for a period up to 15 days at 10ºC, with acceptable quality characteristics.
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The Tahiti acid lime in Brazil is mostly grown in the São Paulo State. The value of this crop production ranks among the ten most important fruits in the country. The Brazilian exports of Tahiti limes have increased in the last years with a corresponding increased demand for superior quality of fresh fruits, which is affected by mineral nutrients. Therefore, this study evaluated nutrient soil availability and its influence on nutritional status of trees based on the determination of leaf and fruit nutrient concentrations, fruit characteristics, and post harvest quality. Eleven commercial groves with trees older than 4-yr and differently managed were studied. Plots with six trees in each grove were sampled for soil (0-20 cm depth layer), leaf and fruit analyses with three replicates. Correlation coefficients were pair wised established for all variables. The results showed that N leaf concentration was well correlated with green color of fruit peel as measured by a color index (r = -0.71**), and which was optimum with Leaf-N around 22 g kg-1. Leaf-Ca was inversely correlated with fruit water loss after 14-day interval from harvest (r = -0.54*) demonstrating that Ca plays an important role in Tahiti fruit shelf-life. Data also suggested that increased fruit K concentration correlated with increased fruit water losses during storage (r >0.58*).
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'Aurora-1' peaches establishes an interesting alternative as a minimally processed product, due to its characteristics like flavor, color, smell, and also because of its handling resistance. However, it has a short shelf life after a fresh-cut due to enzymatic browning and stone cavity collapse. The main purpose of this research was to test the additive with antioxidant effect to prevent browning in minimally processed 'Aurora-1' peaches. The minimal processing consists of washing, sanitizing, peelings and fruit stone extraction. After that, longitudinal cuts were made to obtain eight segments per fruit. The slices were immersed into the following treatment solutions: control (immersion in 2% ascorbic acid); 2% ascorbic acid + 2% calcium chloride; 1% sodium isoascorbate; 1% citric acid; 1% L-cysteine hydrochloride. The products were placed into rigid polystyrene trays branded MEIWA M-54, covered with 14 µm PVC film (OmnifilmTM) and kept in cold storage at 3ºC ± 2ºC and 65% RH for twelve days, and evaluated each three days. Appraised variables were appearance, soluble solids, titratable acidity, soluble carbohydrates and reducing sugars, total and soluble pectin, ascorbic acid, and peroxidase and polyphenol oxidase enzyme activity. L-cysteine gave to the minimally processed products a shelf life of twelve days, limmited by off-flavor. The treatment with ascorbic acid was efficient to maintainthe ascorbic acid content, with a shelf-life of nine days, limited by enzymatic browning.
Resumo:
Vitamin C stability and concentration was evaluated in isotonic beverages and B group vitamins (B1, B2, B3, B5 and B6) in power beverages. The amount of vitamins was found to be above of that declared on the labels, even after the shelf life had been exceeded. A small decrease in the amount of B group vitamins was observed during the shelf life of the products. In the case of vitamin C this decrease was slightly higher. The present research shows the need of increased quality control and inspection.
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Hydrological samples were collected on the continental shelf of the Amazon river to determine particulate organic and inorganic matter, dissolved organic phosphorus (DOP), phosphate, total particulate phosphorus (TPP), chlorophyll a, temperature, salinity, pH, water transparency, dissolved oxygen (DO) and saturation rate. The objective was to study the forms of DOP, phosphate and TPP. In the euphotic layer, the fluvial discharge from the Amazon river favored the distribution of phosphate, TPP and DOP. In the aphotic layer, the phosphate concentration increased due to the decomposition of DOP and TPP. This increase is due to the absence of photosynthetic processes.
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The purpose of this work was to determine the safe shelf life of single-base propellants. The kinetic parameters relative to the consumption of the stabilizer diphenylamine (DPA) added to the propellant were determined as a function of the storage and ageing time. High Performance Liquid Chromatography (HPLC) with spectrophotometric detection was used to determine the DPA percentage before and after the artificial ageing at 60, 70 and 80 ºC. The experimental data were very well adjusted to a pseudo-first order kinetic model and the respective kinetic constants are 8.0-10-3 day-1 (60 ºC); 1.9-10-2 day-1 (70 ºC); 1.2-10-1 day-1 (80 ºC). The activation energy was calculated as 130 kJ mol-1 and the half-time for depletion of the DPA at the hypothetical temperature of 40 ºC of storage was estimated as being 6 years.
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The water content in seafoods is very important since it affects their sensorial quality, microbiological stability, physical characteristics and shelf life. In this study, thermoanalytical techniques were employed to develop a simple and accurate method to determine water content (moisture) by thermogravimetry (TG) and water activity from moisture content values and freezing point depression using differential scanning calorimetry (DSC). The precision of the results suggests that TG is a suitable technique to determine moisture content in biological samples. The average water content values for fish samples of Lutjanus synagris and Ocyurus chrysurus species were 76.4 ± 5.7% and 63.3 ± 3.9%, respectively, while that of Ulva lactuca marine algae species was 76.0 ± 4.4%. The method presented here was also successfully applied to determine water activity in two species of fish and six species of marine algae collected in the Atlantic coastal waters of Bahia, in Brazil. Water activity determined in fish samples ranged from 0.946 - 0.960 and was consistent with values reported in the literature, i.e., 0.9 - 1.0. The water activity values determined in marine algae samples lay within the interval of 0.974 - 0.979.
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Organic markers, such as sterols and ketones, were used to assess sewage contamination in sediments from the Santos Bay, SP, and its continental shelf. These compounds were analyzed by GC/FID after soxhlet extraction, clean up and derivatization. The concentration of coprostanol and ratios between selected sterols were used to evaluate fecal contamination. The stations located in the mid-western part of the Santos Bay presented organic matter from sewage due to the input of fecal material from the city of Santos by submarine sewage outfall. Stations located at the continental shelf did not present fecal contamination. Coprostanol levels in sewage outfall stations were higher in comparison to other Brazilian coastal areas, except Guanabara Bay/RJ, and could be related to the fraction of the population without sewage treatment.
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Sunflower oil is one of the vegetable oils most susceptible to oxidative reaction. Therefore the presence of natural (tocopherol) and/or synthetic (TBHQ) antioxidants is a prerequisite to secure the stability of this oil during its shelf life, especially with the increased use of PET packaging. On determining the total tocopherol content in 10 samples of deodorized sunflower oils, high losses in total tocopherol during deodorization were identified. In order to facilitate researche involving oxidative stability of vegetable oils, a method for isolated quantification of TBHQ using the isocratic elution system was developed.
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In honey 5-hydroxymethyl-2-furaldehyde (HMF) is one of the most typical products of degradation: it is usually absent in fresh honey, but its concentration tends to rise as a result of heating processes or long-term storage. The validation protocol was performed in terms of detection and quantification limits, precision (by repeatability and intermediate precision), linearity and accuracy (by recovery tests). The method has been tested on 15 honey samples of different ages and geographical origin. HMF correlated highly with the age of the samples has been considered a very important parameter to put these honeys on the market or not and/or to estimate their shelf life.
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Several matters of the pharmaceutical demonstrate the great importance of thermal analysis application, especially TG and DSC for the pharmaceutical industry future, namely: characterization of the drugs with the thermal events definition, in studies of drug purity, in the polymorphs identification, in compatibility studies of solid dosage pharmaceutical formulations, in drugs and pharmaceutical formulations thermal stability, and in determination of shelf life for isothermal degradation kinetics by extrapolation using the Arrhenius equation. Thus, the test results obtained from thermal analysis are directly related to the quality of a pharmaceutical product, whether the stability or bioavailability of the pharmaceutical product.