Search results for "DEGRADATION"
showing 10 items of 1208 documents
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 …
Preparation of polycrystalline TiO2 photocatalysts impregnated with various transition metal ions : characterization and photocatalytic activity for …
2002
A set of polycrystalline TiO2 photocatalysts loaded with various ions of transition metals (Co, Cr, Cu, Fe, Mo, V, and W) were prepared by using the wet impregnation method. The samples were characterized by using some bulk and surface techniques, namely X-ray diffraction, BET specific surface area determination, scanning electron microscopy, point of zero charge determination, and femtosecond pump-probe diffuse reflectance spectroscopy (PP-DRS). The samples were employed as catalysts for 4-nitrophenol photodegradation in aqueous suspension, used as a probe reaction. The characterization results have confirmed the difficulty to find a straightforward correlation between photoactivity and si…
Varying chiral ratio of Pinic acid enantiomers above the Amazon rainforest
2023
Chiral chemodiversity plays a crucial role in biochemical processes such as insect and plant communication. However, the vast majority of organic aerosol studies do not distinguish between enantiomeric compounds in the particle phase. Here we report chirally specified measurements of secondary organic aerosol (SOA) at the Amazon Tall Tower Observatory (ATTO) at different altitudes during three measurement campaigns at different seasons. Analysis of filter samples by liquid chromatography coupled to mass spectrometry (LC-MS) has shown that the chiral ratio of pinic acid (C9H14O4) varies with increasing height above the canopy. A similar trend was recently observed for the gas-phase precursor…
Development of a Method for Anodic Degradation of Lignin for the Analysis of Paleo‐Vegetation Proxies in Speleothems
2022
Microbial community analysis, influence of reactor hybridation and effect of the proportion of glycol ethers/ethanol mixtures in EGSB reactors
2018
Antecedentes La emisión de compuestos orgánicos volátiles (COVs) puede causar diferentes problemas en la salud pública y en el medio ambiente, actuando como contaminantes primarios y permitiendo la formación de contaminantes secundarios como el ozono troposférico. Debido a estos problemas, la emisión de COVs está limitada en muchos países tales como EEUU o los pertenecientes a la Unión Europea, en este caso regulado por la directiva 2010/75/EU. Debido al uso de disolventes en su proceso productivo, la industria flexográfica es uno de los sectores que más contribuye a la emisión de este tipo de compuestos, y las técnicas biológicas han sido consideradas como una de las mejores disponibles pa…
Genome and phenotype microarray analyses of rhodococcus sp. BCP1 and rhodococcus opacus R7: Genetic determinants and metabolic abilities with environ…
2015
In this paper comparative genome and phenotype microarray analyses of Rhodococcus sp. BCP1 and Rhodococcus opacus R7 were performed. Rhodococcus sp. BCP1 was selected for its ability to grow on short-chain n-alkanes and R. opacus R7 was isolated for its ability to grow on naphthalene and on o-xylene. Results of genome comparison, includ- ing BCP1, R7, along with other Rhodococcus reference strains, showed that at least 30% of the genome of each strain presented unique sequences and only 50% of the predicted proteome was shared. To associate genomic features with metabolic capabilities of BCP1 and R7 strains, hundreds of different growth conditions were tested through Phenotype Microarray, b…
Combined metabolic activity within an atrazine-mineralizing community enriched from agrochemical factory soil
2007
Abstract The main objective of this work was to characterize an atrazine-mineralizing community originating from agrochemical factory soil, especially to elucidate the catabolic pathway and individual metabolic and genetic potentials of culturable members. A stable four-member bacterial community, characterized by colony morphology and 16S rDNA sequencing, was rapidly able to mineralize atrazine to CO 2 and NH 3 . Two primary organisms were identified as Arthrobacter species (ATZ1 and ATZ2) and two secondary organisms (CA1 and CA2) belonged to the genera Ochrobactrum and Pseudomonas, respectively. PCR assessment of atrazine-degrading genetic potential of the community, revealed the presence…
Elucidation of the biosynthesis and degradation of allantofuranone by isotopic labelling and fermentation of modified precursors.
2010
Feeding experiments with the ascomycete Allantophomopsis lycopodina indicated that the potent fungistatic allantofuranone is biosynthesized from phenylalanine. Further experiments with synthetic precursors gave evidence that the naturally occurring polyporic acid serves as a key intermediate in the biosynthesis. In addition to the formation of allantofuranone, its abiotic and metabolic degradation were investigated.