Search results for "SPM"
showing 10 items of 68 documents
Impact of lipid extraction on the dearomatisation of an Eisenia foetida protein powder
2010
www.elsevier.com/locate/foodchem ; FSTA:2010-Sp0197; International audience; Delipidation was studied as a way to dearomatise a non-conventional protein powder obtained from Eisenia foetida earthworms. In the first step, we studied the impact of several factors such as solvent type, extraction method and particle size on the yield of extracted lipids. Lipid extraction from samples was considerably improved using an ultrasound method with a chloroform/methanol mixture and small particle size. In the second step, the volatile compounds were extracted from the delipidated protein powder by the SAFE extraction method and by the HS-SPME method, and were further analysed by GC-MS. The chloroform/…
Identification of the Trail-Following Pheromone of the Pest Termite Amitermes evuncifer (Isoptera : Termitidae)
2010
International audience; Amitermes evuncifer (Termitidae, Termitinae) is a pest termite in several countries of Africa, damaging crops and buildings. The trail-following pheromone of this termite was isolated from worker sternal glands and identified by GC-MS after solid phase microextraction (SPME). The pheromone is composed of (3Z,67,8E)-dodeca-3,6,8-trien-1-ol (dodecatrienol) and neocembrene acting in synergy, neocembrene being 5-10 times more abundant than dodecatrienol. Dodecatrienol alone is able to elicit trail-following in workers, whereas neocembrene alone is inactive. However, the association of both components induces a significantly higher trail-following activity. Multicomponent…
Sesquiterpene volatile organic compounds (VOCs) are markers of elicitation by sulfated laminarine in grapevine
2015
SPE IPM UB CT1; International audience; Inducing resistance in plants by the application of elicitors of defense reactions is an attractive plant protection strategy, particularly for grapevine (Vitis vinifera), which is susceptible to severe fungal diseases. Although induced resistance (IR) can be successful under controlled conditions, in most cases, IR is not sufficiently effective for practical disease control under outdoor conditions. Progress in the application of IR requires a better understanding of grapevine defense mechanisms and the ability to monitor defense markers to identify factors, such as physiological and environmental factors, that can impact IR in the vineyard. Volatile…
Sensory evaluation of headspace extracts by direct GC-olfactometry : application to fresh orange juice
2002
National audience
A survey of recent results in passive sampling of water and air by semipermeable membrane devices
1995
Abstract A survey is presented of some recent results for passive sampling of water and air for trace organic contaminants using lipid-filled semipermeable membrane devices (SPMDs). Results of water sampling for trace organochlorine compounds using simultaneously exposed SPMDs and the most universally applied biomonitor (bivalves) are discussed. In general, the total amounts of accumulated analytes available for analysis in bivalves and SPMDs were comparable. However, SPMD controls typically had negligible levels of contamination, which was not always the case for transplanted bivalves, even after prolonged depuration prior to exposure. In surveys of the spatial trends of organochlorines at…
Analysis of Contact Traces of Cannabis by In-Tube Solid-Phase Microextraction Coupled to Nanoliquid Chromatography
2018
Because of its inherent qualities, in-tube solid-phase microextraction (IT-SPME) coupled on-line to nanoliquid chromatography (nanoLC) can be a very powerful tool to address the new challenges of analytical laboratories such as the analysis of traces of complex samples. This is the case of the detection of contact traces of drugs, especially cannabis. The main difficulties encountered in the analysis of traces of cannabis plants on surfaces are the low amount of sample available (typically <
Regulation of T-Cell Immune Responses by Pro-Resolving Lipid Mediators
2021
Both the initiation and the resolution of inflammatory responses are governed by the sequential activation, migration, and control/suppression of immune cells at the site of injury. Bioactive lipids play a major role in the fine-tuning of this dynamic process in a timely manner. During inflammation and its resolution, polymorphonuclear cells (PMNs) and macrophages switch from producing pro-inflammatory prostaglandins and leukotrienes to specialized pro-resolving lipid mediators (SPMs), namely, lipoxins, resolvins, protectins, and maresins, which are operative at the local level to limit further inflammation and tissue injury and restore homeostasis. Accumulating evidences expand now the rol…
Desarrollo de estrategías analíticas para la identificación de contaminantes emergentes
2015
En la presente Tesis, se han desarrollado diferentes métodos para identificar la presencia de contaminantes procedentes de diferentes fuentes naturales. Los métodos desarrollados han sido abordados utilizando dos metodologías: (i) IT-SPME acoplado a CapLC y UHPLC con detección DAD y MS, y (ii) dispositivos de análisis in situ. La estrategia basada en el acoplamiento entre IT-SPME y CapLC y UHPLC se ha utilizado para la estimación de la presencia de contaminantes (pesticidas como triazinas, nitroanilina, fenilureas y organofosforados, y plastificantes como productos de degradación del DEHP y principalmente DEHP) en muestras de aguas superficiales, de aguas de depuradoras, biota y sedimentos.…
Partition of volatile compounds in pea globulin–maltodextrin aqueous two-phase system
2014
International audience; This study is based on the assumption that the off-flavour of pea proteins might be decreased using the retention of volatile compounds by a mixture with another biopolymer. The partition of volatile compounds in an aqueous system containing pea protein and maltodextrins was followed under thermodynamic incompatibility conditions. Firstly, the phase diagram of the system was established. Then, the partition of aroma compounds between the phase rich in protein and the phase rich in maltodextrin was measured by SPME–GC–MS. There was a transfer of volatile compounds during phase separation. Variations of pH were also used to vary the retention of volatile compounds by p…
Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿
2010
ABSTRACT Enzymes involved in oxidation of long-chain n -alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n -alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n -alkanes from dodecane (C 12 ) to hexatriacontane (C 36 ) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4…