Search results for "Gradation"
showing 10 items of 1275 documents
Stability of vacuolar betaxanthin pigments in juices from Moroccan yellow Opuntia ficus indica fruits
2008
Pigment stability of yellow juices prepared from Moroccan cactus pear (Opuntia ficus indica) was determined as a function of temperature and pH. The experiments were carried out at temperatures ranging from 80 to 100 °C with juices at pH 3.5, 5 and 6.5. The degree of pigment retention decreased when the temperature increased. The degradation constant rates were determined for thermal degradation rates of pseudo-first order. The Arrhenius plot obtained for the degradation of betaxanthin from the yellow fruits was not linear. Regardless of the temperature treatment, the lowest degradation was obtained for pH 5. Where some stabilizers were tested for the protection of pigments, the results sho…
Monod-based ‘single-data’ strategy for biodegradation screening tests
2020
Environmental contextObtaining biodegradation data over time can be difficult, especially when dealing with environmental compartments of increasing complexity. We evaluated the possibility of obtaining a full biodegradation depletion curve from a single biodegradation-time experimental measurement, and found that environmental information related to potential chemical persistence can be derived. The applicability of this ‘single-data’ strategy is illustrated using simulated and experimental data for several compounds. AbstractInformation obtained from biodegradability tests, e.g. half-life (t50) or kinetics parameters, is relevant in environmental risk assessment of new chemicals. In thes…
From ‘polluter pays’ to ‘polluter does not pollute’
2016
Abstract Non-binding agreements, minor sanctions in the form of payment obligations and shaming have been the usual policy responses against environmental harms. In addition to this, many existing pieces of legislation on international environmental law and governance are based on good intent and voluntary agreement and they have proven to be limited or ineffective. This article argues that, at the current state of the climate crisis, there is no more room for negotiations and proposals which lead to false solutions. Acknowledging that, legal solutions to environmental problems require new formulations which incorporate a different understanding of nature and its non-human inhabitants; this…
Managing arbuscular mycorrhizal fungi in cropping systems
2005
Market globalization, demographic pressure, and environmental degradation have led us to reconsider many of our current agricultural systems. The heavy use of chemical inputs, including fertilizers and pesticides, has resulted in pollution, decreased biodiversity in intensively-farmed regions, degradation of fragile agro-ecosystems, and prohibitive costs for many farmers. Low input sustainable cropping systems should replace conventional agriculture, but this requires a more comprehensive understanding of the biological interactions within agro-ecosystems. Mycorrhizal fungi appear to be the most important telluric organisms to consider. Mycorrhizae, which result from a symbiosis between th…
2,4-D impact on bacterial communities, and the activity and genetic potential of 2,4-D degrading communities in soil
2006
The key role of telluric microorganisms in pesticide degradation is well recognized but the possible relationships between the biodiversity of soil microbial communities and their functions still remain poorly documented. If microorganisms influence the fate of pesticides, pesticide application may reciprocally affect soil microorganisms. The objective of our work was to estimate the impact of 2,4-D application on the genetic structure of bacterial communities and the 2,4-D-degrading genetic potential in relation to 2,4-D mineralization. Experiments combined isotope measurements with molecular analyses. The impact of 2,4-D on soil bacterial populations was followed with ribosomal intergenic…
Effect of cactus pear cultivation after Mediterranean maquis on soil carbon stock, δ13C spatial distribution and root turnover
2014
Abstract Mediterranean ecosystems are characterized by nearly complete replacement of natural vegetation by intensive croplands and orchards leading to strong soil degradation. Organic carbon is usually accumulated in soils under maquis leading to partial regeneration of fertility for future agricultural use. The aim of this work was to investigate the effect of land use change from maquis to agriculture on soil organic carbon (SOC) stock and its spatial distribution in a Mediterranean system. Three Mediterranean land use systems (seminatural vegetation, cactus pear crop and olive grove) were selected in Sicily and analysed for soil C stocks and their δ13C. Total SOC and δ13C were measured …
Evidence for 2,4-D mineralisation in Mediterranean soils: impact of moisture content and temperature
2009
BACKGROUND: The 2,4-D degradation ability of the microbiota of three arable Mediterranean soils was estimated. The impact of soil moisture and temperature on 2,4-D degradation was investigated. RESULTS: The microbiota of the three soils regularly exposed to 2,4-D were able rapidly to mineralise this herbicide. The half-life of 2,4-D ranged from 8 to 30 days, and maximum mineralisation of 14C-2,4-D ranged from 57 to 71%. Extractable 14C-2,4-D and 14C-bound residues accounted for less than 1 and 15% respectively of the 14C-2,4-D initially added. The highest amounts of 14C-2,4-D bound residues were recorded in the soil with the lowest 2,4-D-mineralising ability. Although all three soils were a…
Untargeted metabolomics to explore the oxidation processes during shelf life of pork patties treated with guarana seed extracts
2019
The changes of metabolites in pork patties with different antioxidants added (control without antioxidants, 200 mg kg(-1) butylated hydroxytoluene (BHT) and 250 mg kg(-1) guarana seed extracts (GSEs)) under modified atmosphere (80% O-2 and 20% CO2) for 18 days of refrigerated storage were evaluated. Untargeted metabolomic approach based on UHPLC-ESI-QTOF-MS analysis was applied. GSE phytochemical profile revealed a wide variety of compounds (caffeine, glycerol 1-propanoate, amino acids, alkaloids and glycerophospholipids), together with antioxidants (tyrosols, procyanidins and flavonoids). Important differences in BHT and GSE patties metabolomic profiles were found during storage. Most of t…
Extra-virgin olive oils storage: Effect on constituents of biological significance
2021
Abstract The high oxidative stability of virgin olive oil with respect to other vegetable oils is mainly due to its fatty acid composition, in particular, to the high monounsaturated-to-polyunsaturated ratio, and to the presence of minor compounds that play a major role in preventing oxidation. In spite of its high stability, virgin olive oil is susceptible to oxidative processes, such as enzymatic oxidation, photooxidation, and autoxidation, which mainly occur during processing and storage. Generally, extra-virgin olive oil has a relatively long shelf life of 16–18 months of storage at room temperature. The study of shelf life is generally based on determining of quality parameters (acidit…
Green Composites Based on PLA and Agricultural or Marine Waste Prepared by FDM
2021
Three dimensional-printability of green composites is recently growing in importance and interest, especially in the view of feasibility to valorize agricultural and marine waste to attain green fillers capable of reducing bioplastic costs, without compromising their processability and performance from an environmental and mechanical standpoint. In this work, two lignocellulosic fillers, obtained from Opuntia ficus indica and Posidonia oceanica, were added to PLA and processed by FDM. Among the 3D printed biocomposites investigated, slight differences could be found in terms of PLA molecular weight and filler aspect ratio. It was shown that it is possible to replace up to 20% of bioplastic …