34,017 research outputs found

    Fungal solid state fermentation on agro-industrial wastes for acid wastewater decolourization in a continuous flow packed-bed bioreactor

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    This study was aimed at developing a process of solid state fermentation (SSF) with the fungi Pleurotus ostreatus and Trametes versicolor on apple processing residues for wastewater decolorization. Both fungi were able to colonize apple residues without any addition of nutrients, material support or water. P. ostreatus produced the highest levels of laccases (up to 9 U g-1 of dry matter) and xylanases (up to 80 U g-1 of dry matter). A repeated batch decolorization experiment was set up with apple residues colonized by P. ostreatus, achieving 50% decolorization and 100% detoxification after 24 h, and, adding fresh wastewater every 24 h, a constant decolorization of 50% was measured for at least 1 month. A continuous decolorization experiment was set up by a packed-bed reactor based on colonized apple residues achieving a performance of 100 mg dye L-1 day-1 at a retention time of 50

    The influence of lime sulphur on the quality and sulphur content of organic 'Royal Gala' and 'Braeburn' apples : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Agribusiness at Massey University

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    Black spot or apple scab is a major disease in apple (Malus domestica) production. Its control is especially difficult in organic production systems that rely on copper- and sulphur-based fungicides which are not very effective and demand a high number of applications throughout the season. The most commonly used fungicide in organic apple production is lime sulphur, which is known to be phytotoxic, especially towards the cultivar 'Braeburn'. The influence of different application rates of lime sulphur (1% anti 2%) was evaluated when applied 11 times throughout the growing season from October to February. As varieties differ in their susceptibility to lime sulphur, the two cultivars 'Royal Gala' and 'Braeburn' were compared in this study. Black spot incidence and severity, russet development and postharvest quality parameters were evaluated. At harvest, residues of sulphur on and in the apple were determined as total sulphur, total water-soluble non-protein thiol compounds and cysteine content. Both cultivars behaved similarly to the application of lime sulphur, but 'Braeburn' was affected to a greater extent. Lime sulphur decreased background colour, blush, firmness, soluble solids content and dry matter content in both cultivars; fruit size in 'Braeburn' and titratable acidity in 'Royal Gala'. The changes observed can possibly be attributed at least in part to the decrease in the photosynthetic rate, which was especially drastic in 'Braeburn'. Lime sulphur caused increased russet on 'Royal Gala', but not on 'Braeburn'. Significant sulphur residues were found in the skin and flesh of both cultivars and part of the lime sulphur applied was metabolized into water-soluble non-protein thiols and cysteine. These results are of significant interest to the organic industry as the use of lime sulphur may compromise the residue-free status of organic apples and could have an influence on consumer acceptance and flavour

    Pesticides Residues and Trade: the Apple of Discord?

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    The impact of food safety standards on international trade has already been addressed. Generally, economists try to assess trade losses borne by exporters when importing countries impose stricter regulations. In this paper we assess the impact of the Maximum Residue Levels (MRL) of pesticides on the trade of apples and pears. Rather than focusing on a particular pesticide we take into account the entire list of substances set out by the various regulations with the aim is to understand how the similarity (or dissimilarity) of these can affect trade. Most studies assess the impact of sanitary standard regulations introducing directly in the analysis the MLR put in force in the importing country. We assume that what can be crucial is the difference in the tolerance levels of both the importing and exporting country. Having built a similarity index we then introduce it into a gravity equation to assess the impact of differences in MRL of pesticides on the trade of apples and pears of seven exporting and seven importing countries. Results suggest that harmonizing regulations impacts trade differently depending on the exporter.food safety, standards, pesticides, MRL, apple, pear, market access, Crop Production/Industries, International Relations/Trade, Q17, F13,

    Matrix-Matching as an Improvement Strategy for the Detection of Pesticide Residues

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    More than 90% of the pesticides residues in apples are located in the peel. We developed a gas chromatography/ion trap tandem mass spectrometry method for investigating all detectable residues in the peel of 3 apple varieties. Sample preparation is based on the use of the Quick Easy Cheap Effective Rugged and Safe method on the whole fruit, the flesh, and the peel. Pesticide residues were quantified with solvent‚Äźmatched and matrix‚Äźmatched standards, by spiking apple sample extracts. Matrix effects dependent on the type of extract (fruit, flesh, or peel) and the apple variety were detected. The best data processing methods involved normalizing matrix effect rates by matrix‚Äźmatched internal/external calibration. Boscalid, captan, chlorpyrifos, fludioxonil, and pyraclostrobin were the most frequently detected pesticides. However, their concentrations in the whole fruit were below European maximum residue levels. Despite negative matrix effects, the residues in peel were detected at concentrations up to 10 times higher than those in whole fruits. Consequently, other pesticide residues present at concentrations below the limit of quantification in the whole fruit were detected in the peel

    Brazilian monitoring programs for pesticide residues in food ‚Äď Results from 2001 to 2010

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    AbstractA total of 13,556 samples of 22 fruit and vegetable crops, rice, and beans were analyzed within two Brazilian pesticide residue monitoring programs between 2001 and 2010. Pesticide residues were found in 48.3% of the samples, and 13.2% presented some irregularity, mostly non-authorized active ingredient use. Less than 3% of the samples had residue levels above the MRL. Apple, papaya, sweet pepper and strawberry were the crops with the higher percentages of positive samples (about 80%). Dithiocarbamates and organophosphorus compounds were found in 41.6% and 30.8% of the samples, respectively. Carbendazim and chlorpyrifos were the pesticides most found (26.7 and 16.1% of positive samples, respectively). Almost half of the samples analyzed had multiple residues (up to 10 residues), with multiple residues most common in samples of apple, sweet pepper and tomato. About 8% of positive samples contained up to four residues of the same chemical class, mainly organophosphorus compounds (18.6%, mostly in apple) and triazoles (16.1%, mostly in papaya and grape). In general, the scenario of pesticide residues in foods investigated within the Brazilian governmental monitoring programs in the last decade is similar to what has been found in other countries. However, the use of non-authorized active ingredients is a common practice among the farmers in the country, a problem that the government authorities have been trying to solve. A preliminary cumulative acute exposure assessment for organophosphates and carbamates in apple has shown that the intake by individuals ‚Č•10 years old accounts for 100% of the acephate ARfD, indicating a need to further investigate the exposure through the consumptions of other crops and group of pesticides, mainly for children

    Harvesting orchard pruning residues in southern Piedmont: a first evaluation of biomass production and harvest loss

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    In recent years, interest in farming residues has grown and orchard pruning residues are no exception. Several factors define pruned branch mass and dimensional characteristics: fruit variety, vigor, training system used, and pruning intensity and periodicity. While many studies have been performed to determine residue biomass availability, dating and surveying are not always accurate. Detailed qualitative and quantitative knowledge is needed to evaluate the economic sustainability of exploiting orchard pruning residues as an energy source. To assess the real chain potential of renewable energy production from orchard pruning residues in the area of Cuneo, in the Region of Piedmont, northwestern Italy, a study was conducted on the species Actinidia (kiwi tree) pruned according to the Peyracchia system, and Malus (apple tree) pruned according to two different systems, i.e. traditional and taille longue. For each species, pruning residue amounts were quantified and their basal diameter measured. Surveys were performed on some half trees, spaced as crop, for three randomised replications. Pruning residues were determined by dynamometer (accuracy 0.02N); individual cut-off branch diameters were measured at their base with mechanical calipers. Pruning residues were blown by rotating rake and harvested by a modified fixed chamber round baler. Harvest losses were determined by the methodology used for the initial residue quantification. Results showed the average biomass availability was 2.51 Mg DM ha‚Äď1 (SD 0.83) for kiwi tree, 3.04 Mg DM ha‚Äď1 (SD 1.17) for traditionally-pruned apple trees, and 0.46 Mg DM ha‚Äď1 (SD 0.36) for apple trees pruned with the taille longue system. Harvest losses (total pruned dry mass) averaged approximately 19% in kiwi trees and 16% in apple trees (95% to 10% for variety

    Removal of heavy metal from aqueous solution by apple residues / Norliati Mohamed Nakman

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    This study is carried out to investigate the ability of apple residues to remove heavy metal from aqueous solution. Apple residues are considered as one of the agricultural wastes can be used as adsorbents. The optimum condition in the removal of lead, cadmium and chromium by apple residues was studied by varying all parameters which affect the biosorption of apple residues on heavy metals. These include optimum pH of biosorption, effect of adsorbent dosage and effect of initial metal concentration. The sample then was analyze using Atomic Absorption Spectrometer

    Integrated disease management

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    Integrated disease management in organic farming combines the use of various measures. The usefulness of certain measures depends on the specific crop-pathogen combination. In many crops, preventative measures can control diseases without the need of plant protection products. However, for certain disease problems, preventative measures are not sufficient. For example, organic apple production strongly depends on the multiple use plant protection products

    Results of routine testing of organic food for agro-chemical residues

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    This report was presented at the UK Organic Research 2002 Conference. Consumers expect organic foods to be free of agro-chemical residues. Organix Brands plc. routinely test organic food ingredients for agrochemical residues using independent test laboratories. In the past year 243 batches of ingredients were tested and low levels of agro-chemical residues were found in 21% of samples. These residues can arise in organic food through environmental contamination, processing contamination or even the fraudulent use of agro-chemicals on organic food. Food containing agro-chemical residues can enter the organic system because of limitations in the organic rule
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