1,980 research outputs found

    Effect of home-refrigerator storage temperature on tomato quality

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    Postharvest storage, handling and distribution of fruit at low temperatures is the most common and manageable approach to control ripening and subsequent deterioration and to maximize product shelf-life. However, tomatoes, as many other subtropical fruits, are susceptible to develop symptoms of chilling injury, a physiological disorder caused by the exposure to low temperature above the freezing point. Development of chilling injury depends on temperature, time, ripening stage and tomato type/cultivar. We studied the effect of home-refrigerator storage temperature on the quality of two types of tomato: cocktail tomato (cultivars ‘Amoroso’ and ‘Brioso’) and truss tomato (cultivars ‘Capricia’ and ‘Roterno’). Fully ripe tomatoes were stored for 10 days at two temperatures: 4°C as simulation of home-refrigerator storage and 15°C as an optimal storage temperature. We evaluated several quality parameters: weight loss, firmness, soluble solid content, titratable acidity, carbohydrates, titratable acidity and citrate content. Although we did not observe any apparent symptom of chilling injury, we found that 4°C temperature stimulates firmness decay in both cocktail tomato cultivars, increasing fruit susceptibility to mechanical injury. Moreover, already after 5 days of 4°C storage, tomatoes generally showed decreased sugar and increased acid content (especially in cocktail tomatoes) compared to 15°C stored fruit, indicating a loss of sensoric quality at 4°C

    Simulation of 3D Model, Shape, and Appearance Aging by Physical, Chemical, Biological, Environmental, and Weathering Effects

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    Physical, chemical, biological, environmental, and weathering effects produce a range of 3D model, shape, and appearance changes. Time introduces an assortment of aging, weathering, and decay processes such as dust, mold, patina, and fractures. These time-varying imperfections provide the viewer with important visual cues for realism and age. Existing approaches that create realistic aging effects still require an excessive amount of time and effort by extremely skilled artists to tediously hand fashion blemishes or simulate simple procedural rules. Most techniques do not scale well to large virtual environments. These limitations have prevented widespread utilization of many aging and weathering algorithms. We introduce a novel method for geometrically and visually simulating these processes in order to create visually realistic scenes. This work proposes the ``mu-ton system, a framework for scattering numerous mu-ton particles throughout an environment to mutate and age the world. We take a point based representation to discretize both the decay effects and the underlying geometry. The mu-ton particles simulate interactions between multiple phenomena. This mutation process changes both the physical properties of the external surface layer and the internal volume substrate. The mutation may add or subtract imperfections into the environment as objects age. First we review related work in aging and weathering, and illustrate the limitations of the current data-driven and physically based approaches. We provide a taxonomy of aging processes. We then describe the structure for our ``mu-ton framework, and we provide the user a short tutorial how to setup different effects. The first application of the ``mu-ton system focuses on inorganic aging and decay. We demonstrate changing material properties on a variety of objects, and simulate their transformation. We show the application of our system aging a simple city alley on different materials. The second application of the ``mu-ton system focuses organic aging. We provide details on simulating a variety of growth processes. We then evaluate and analyze the ``mu-ton framework and compare our results with ``gamma-ton tracing. Finally, we outline the contributions this thesis provides to computer-based aging and weathering simulation

    Withering Fruits: Vegetable Matter Decay and Fungus Growth

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    We propose a parametrised method for recreating drying and decaying vegetable matter from the fruits category, taking into account the biological characteristics of the decaying fruit. The simulation addresses three main phenomena: mould propagation, volume shrinking and fungus growth on the fruit's surface. The spread of decay is achieved using a Reaction-Diffusion method, a Finite Element Method is used for shrinking and wrinkling of the fruit shell, while the spread of the fruit's fungal infection is described by a Diffusion Limited Aggregation algorithm. We extend existing fruit decay approaches, improving the shrinking behaviour of decaying fruits and adding independent fungal growth. Our approach integrates a user interface for artist directability and fine control of the simulation parameters

    Optimal Handling and Postharvest Strategies to Reduce Losses of ‘Cuello Dama Negro’ Dark Figs (Ficus Carica L.)

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    The optimal postharvest handling to reduce postharvest decay and maintain quality of ‘Cuello Dama Negro’ fresh dark figs grown in Spain is been studied. Different storage temperatures (0ºC and 4ºC), relative humidity (RH, 75% to 95%) and cooling strategies (delayed and intermittent cooling) were tested. Moreover, different postharvest strategies such as 1-MCP (10 ppm), two different passive modified atmosphere packaging (Xtend® and LifePack MAP), and SO2 generating pads (UVASYS, Grapetek (Pty) Ltd.), were also tested. Storage at 0ºC, 95% RH together with MAP effectively decreased postharvest rots and therefore increased the market life of ‘Cuello Dama Negro’ fresh figs, without altering the fruit quality nor the consumer liking degree. No improvement on the shelf life of the fruit was observed with the application of 1-MCP. The use of SO2 generating pads reduced the decay but detrimentally affected fruit quality by inducing skin bleaching. Low temperature from harvest to consumption is crucial for a good maintenance of quality in fresh fig. In addition, EMAP technology is a low-cost technology able to reduce decay and maintain fruit quality of fresh figs up to 2 weeks.info:eu-repo/semantics/acceptedVersio

    Biologically-based strategies to reduce postharvest losses of tomato

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    The preharvest employment of Bacillus subtilis was highly effective in an augmentation of fruit set and improves general apperance of tomato at harvest. Cooling technology supported the poential of B. subtilis, in particularly prevention of postharvest losses of tomato fruits within marketing context. Furthermore, the resultant inhibition of color development and improvement of sensory traits of tomato fruits due to the preharvest application of our formulated B. subtilis with the help of cooling technology were indicative of general inhibition of senescence and ripening. This biologically-based strategy deserves further development and application under commercial requirements especially in developing countries like Egypt, where refrigeration is inadequate.Key words: Biological control, general appearance, Bacillus subtilis

    Effect of modified atmosphere package on physico-chemical properties of pomegranate (Punica granatum L.) fruits

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    Pomegranate is an important table and processed fruit owing to its nutritional quality. Extending the fruit life of the plant is very much limited owing to its metabolic activities viz., respiration, transpiration and microbial infection. An experiment was conducted to investigate the effect of different packaging materials on physico-chemical properties of pomegranate fruits during storage. Fruits were harvested with stalk and washed with sodium hypochlorite, air dried and graded. Fruits were stored under modified atmospheric packaging conditions using different packaging materials viz., polyethylene bag, polypropylene bag, Xtend® bag and silver nano bag Hima Fresh®. Fruits without package served as controls. Fruits were stored at low temperature 7±2 °C and 90±5 % RH. MAP treated fruits had higher quality parameters across all packaging treatments. PLW and respiration rate increased while, moisture content, colour, texture and acidity decreased with prolonged storage, but the rate of decrease was highest in unpacked fruits. MAP maintained the quality of pomegranate fruits upto 100 days compared to unpackaged fruits (40 days). Shelf life of stored fruit at ambient condition was 4 to 5 days. Fruit decay was 12 % in polyethylene whereas it was 6 % in Xtend® bag at the end of 100 day of storage

    Effects of environmental factors on development of Pyrenopeziza brassicae (light leaf spot) apothecia on oilseed rape debris

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    Publication no. P-2001-0221-01R. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 2001The development of Pyrenopeziza brassicae (light leaf spot) apothecia was studied on petiole debris from artificially infected oilseed rape leaves incubated at temperatures from 6 to 22 degreesC under different wetness regimes and in 16 h light/8 h dark or continuous darkness. There was no significant difference between light treatments in numbers of apothecia that developed. Mature apothecia developed at temperatures from 5 to 18 degreesC but not at 22 degreesC. The rate of apothecial development decreased as temperature decreased from 18 to 5 degreesC; mature apothecia were first observed after 5 days at 18 degreesC and after 15 days at 6 degreesC. Models were fitted to estimates of the time (days) for 50% of the maximum number of apothecia to develop (t(1); model 1, t(1) = 7.6 + 55.8(0.839)(T)) and the time for 50% of the maximum number of apothecia to decay (t(2); model 2, t(2) = 24.2 + 387(0.730)(T)) at temperatures (T) from 6 to 18 degreesC. An interruption in wetness of the petiole debris for 4 days after 4, 7, or 10 days of wetness delayed the time to observation of the first mature apothecia for approximate to4 days and decreased the number of apothecia produced (by comparison with continuous wetness). A relationship was found between water content of pod debris and electrical resistance measured by a debris-wetness sensor. The differences between values of tl predicted by model 1 and observed values of t(1) were 1 to 9 days. Model 2 did not predict t(2); apothecia decayed more quickly under natural conditions than predicted by model 2.Peer reviewe

    Physical, Chemical and Processing Postharvest Technologies in Strawberry

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    Strawberry (Fragaria × ananassa) is a fruit of great acceptance worldwide but has characteristics that make it a highly perishable fruit, with shelf life of about a week, which makes it difficult to transport and store it to consumer places. Throughout the years, post-harvest techniques have been studied to extend their useful life and improve their properties. Strawberry deterioration may be due to various factors such as overripe, fungal involvement, moisture loss, mechanical damage, among others. Among the techniques which have been tried to slow the deterioration of the fruit are the use of modified atmospheres and treatments gases, use of edible coatings and smart packings, application of radiation of various types, use of chemical treatments among many others. In this chapter, we will examine the most relevant treatments applied to the strawberry to extend its useful life and improve its organoleptic quality that have been reported in the literature
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