Influence Of Volatile Compounds Research Articles

Development of Synthetic Aqueous Oil and Grease Standards for Determination of TOG in Produced Water: Evaluation of Alternative Methods for Application in an Offshore Environment.

Produced water is present in oil and natural gas reservoirs and is transported to the surface along with the oil. Total oil and grease content (TOG) is the main parameter evaluated in this waste disposal category. Today, the validation of methods in the laboratory is not done using petroleum. The objective of this work was to develop synthetic oily water standards that can be applied for internalization and validation in the laboratory. Oil weighing protocols, the influence of volatile compounds, and a procedure for preparing oily water with high reproducibility were studied. Synthetic oily water standards were prepared for TOG determination by gravimetric and infrared methods. Repeatability of 3.8 and 11% and accuracy of 85 and 105% were obtained using gravimetric and infrared methods. These results indicate that with the development of these standards, it is possible to validate methodologies for TOG determination using petroleum.

Roles of Fungal Volatiles from Perspective of Distinct Lifestyles in Filamentous Fungi.

Volatile compounds (VOCs) are not only media for communication within a species but also effective tools for sender to manipulate behavior and physiology of receiver species. Although the influence of VOCs on the interactions among organisms is evident, types of VOCs and specific mechanisms through which VOCs work during such interactions are only beginning to become clear. Here, we review the fungal volatile compounds (FVOCs) and their impacts on different recipient organisms from perspective of distinct lifestyles of the filamentous fungi. Particularly, we discuss the possibility that different lifestyles are intimately associated with an ability to produce a repertoire of FVOCs in fungi. The FVOCs discussed here have been identified and analyzed as relevant signals under a range of experimental settings. However, mechanistic insight into how specific interactions are mediated by such FVOCs at the molecular levels, amidst complex community of microbes and plants, requires further testing. Experimental designs and advanced technologies that attempt to address this question will facilitate our understanding and applications of FVOCs to agriculture and ecosystem management.

Isolation of bacteria at different points of Pleurotus ostreatus cultivation and their influence in mycelial growth

Pleurotus ostreatus is one of the most cultivated edible mushrooms worldwide and few approaches have been done to analyze bacterial influence during its cultivation. Therefore, bacteria from commercial spawn, mycelial-colonized straw and fruiting bodies from healthy productive samples were counted, isolated and tested for their mycelial growth promoting ability. Bacterial cell numbers at different steps of the process showed low bacterial cell numbers in spawn and in fruiting bodies inner tissue compared to the high concentration in mycelial-colonized straw. The majority of the 38 isolates belonged to phyla Firmicutes and Actinobacteria were identified as Bacillus, Paenibacillus and Micromonospora species. Similarly, 16S rRNA gene bacterial clones obtained from mycelial biomass DNA samples showed bacterial presence of various genera including Bacillus and Paenibacillus.In the mycelial growth promoting ability tests, 30 isolates negatively affected mycelial growth, two isolates showed no effect on mycelial growth, and six isolates promoted mycelial growth. Moreover, mycelial thickness was influenced in different ways by the bacterial growth. In general, nearly all isolates growth-preventing were isolated from healthy spawn and mycelial-colonized straw, whereas fruiting bodies were the best source for isolation of mycelial growth-promoting bacteria. Characterization of bacterial isolates revealed that growth-preventing isolates exhibited various enzymatic activities in comparison with positive influencing bacteria that exhibited none or weak enzymatic activities. In addition, the influence of volatile compounds being present in the headspace of bi-plate co-cultures on P. ostreatus mycelial growth was demonstrated.The effect of isolates, that promoted mycelial growth in co-cultivation, to reduce P. ostreatus spawn running time, was evaluated on sterilized rye seeds. Results showed that not all mycelial promoted isolates were able to significantly promote P. ostreatus colonization. However, isolate M46F identified as Micromonospora lupini significantly reduce spawn running time. This is one of few studies to estimate cultivable bacteria from healthy samples of P. ostreatus cultivation, to evaluate a bacterial effect on mycelial growth, to show that fruiting bodies are a good source for mycelia growth-promoting isolates, and the first to report a shorter P. ostreatus spawn running time due to bacterial inoculation.

Influence of volatile compounds on flavour of selected cultivars of gooseberry

The flavour of seventeen red, yellow and green varieties of gooseberry (Ribes grossularia L.) was investigated in this study during two consequent years (2014–2015). Taste, odour, flavour descriptors (sweet, acid/sour, astringent) and off-flavour, together with appearance, colour, texture (firmness, crispiness) and overall acceptability were evaluated sensorially using line scale. Related volatile compounds were assessed by solid-phase microextraction coupled to gas chromatography–mass spectrometry. The significant differences (p 1) are considered to contribute to flavour/acceptability of gooseberry samples.

Development of a Rapid Discrimination Tool for Luzhou-flavor Pit Mud Classification by the Kohonen Artificial Neural Network Model

Understanding the volatile composition of pit mud (PM) samples and discriminating these samples has become a highly necessary task, owing to the fact that volatile profiling of PM can significantly affect Chinese Luzhou-flavor liquor quality. In this study, the volatile constitutions of 13 Luzhou-flavor liquor PM samples from four typical producing regions were investigated by gas chromatography–mass spectrometry (GC-MS). Owing to their high concentrations, compounds such as ethyl hexanoate, butyric acid, hexanoic acid, ethyl pentadecanoate, ethyl palmitate, ethyl (9E)-9-octadecenoate, ethyl (9E,12E)-9,12-octadecadienoate, and palmitic acid were considered to be predominant volatiles. A promising artificial neural network model, the Kohonen self-organizing map (SOM), was applied to rapidly discriminate the PM samples in terms of differences based on the quantitative information of volatile compounds. After Kohonen SOM training, 13 distinct clusters, corresponding to PM samples, were clearly visualized on a uniform distance matrix (U-matrix). The influence of volatile compounds on the classification of the PM could be displayed using component panels, which can give quantitative insight. GC-MS coupled with the Kohonen SOM model not only presented the volatile constitution of PM but also provided promising information for discrimination between different PM samples, even in other fermented foods.

Influence of host origin on host choice of the parasitoid Dinarmus basalis: does upbringing influence choices later in life?

The aim of this study was to investigate the influence of volatile compounds from four secondary host plants on the ability of Dinarmus basalis Rond. (Hymenoptera: Pteromalidae) to locate, recognize, and parasitize its host, 4 th instar larvae or pupae of Callosobruchus maculatus F. (Coleoptera: Chrysomelidae). To examine this, strains of D. basalis were transferred from cow-pea seeds ( Vigna unguiculata (L.) Walp. (Fabales: Fabaceae)) to pigeon pea ( Cajanus cajan (L.) Millsp.) and two varieties of Bambara groundnut ( Vigna subterranea (L.) Verdc.) seeds. The ability of D. basalis females to recognize the volatile compounds emanating from their complex host plant was tested by using a Y-tube olfactometer and a three-dimensional device. The results suggest that when females have a choice between pure air and the air emanating from their com-plex host of origin, they are attracted to the air tainted by the volatile compounds they have become accustomed to. They spent significantly more time ( p < 0.0001) in the branch of the tube leading to the odorous air than in the tube leading to the pure air. When females from pigeon pea seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4 th instar larvae, the familiar odor of pigeon pea seeds were most attractive. When females from Bambara groundnut (white and striped) seed hosts were offered a choice between cowpea and pigeon pea seeds, all containing 4 th instar larvae, they were significantly attracted to the odour of cowpea seeds. In the three-dimensional system, the females from the four strains did not appear to have any preference for a given type of seed containing 4 th instar larvae or pupae. The parasitism rate remained high on all four types of seeds used. These results show that the use of D. basalis as a biological control agent is possible in host changing situations where C. maculatus starts to attack other legumes. The results of this study also provide information supporting the behavioral plas-ticity of D. basalis . Understanding the mechanisms involved in the adaptive phenomena of biological control agents is discussed in the context of the development of adequate methods of pest control.

Influence of volatile compounds from herbivore‐damaged soybean plants on searching behavior of the egg parasitoid Telenomus podisi

AbstractParasitoids use herbivore‐induced plant volatiles (HIPVs) to locate their hosts. However, there are few studies in soybean showing the mechanisms involved in the attraction of natural enemies to their hosts and prey. The objective of this study was to evaluate the influence of volatile organic compounds (VOCs) of soybean, Glycine max (L.) Merr. (Fabaceae) (cv. Dowling), that were induced after injury caused by Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), on the searching behavior of the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Scelionidae). Four HIPVs from soybean, (E,E)‐α‐farnesene, methyl salicylate, (Z)‐3‐hexenyl acetate, and (E)‐2‐octen‐1‐ol, were selected, prepared from standards at various concentrations (10−6 to 10−1 m), and tested individually and in combinations using a two‐choice olfactometer (type Y). Telenomus podisi displayed a preference only for (E,E)‐α‐farnesene at 10−5 m when tested individually and compared to hexane, but they did not respond to the other compounds tested individually at any concentration or when combinations of these compounds were tested. However, the parasitoids stayed longer in the olfactometer arm with the mixture of (E,E)‐α‐farnesene + methyl salicylate at 10−5 m than in the arm containing hexane. The results suggest that (E,E)‐α‐farnesene and methyl salicylate might help T. podisi to determine the presence of stink bugs on a plant. In addition, bioassays were conducted to compare (E,E)‐α‐farnesene vs. the volatiles emitted by undamaged and E. heros‐damaged plants, to evaluate whether (E,E)‐α‐farnesene was the main cue used by T. podisi or whether other minor compounds from the plants and/or the background might also be used to locate its host. The results suggest that minor volatile compounds from soybean plants or from its surroundings are involved in the host‐searching behavior of T. podisi.

Influence of volatile compounds and food preservatives in the management of fumonisins (B1) production by Fusarium moniliforme

Efficacy of volatile compounds and food preservatives in the management of fumonisins B 1 production by Fusarium moniliforme was assessed in vitro . The toxin production was analyzed by thin layer chromatographic technique. Among different volatile compounds studied, formic acid and propionic acid inhibited the growth and fumonisins (B1) production by F. moniliforme . Aniline, benzaldehyde, and formaldehyde can suppress fumonisisin B1 production to maximum extent. Camphor at a concentration of 15 mg/ml could inhibit fumonisin B 1 production among different food preservatives studied. From the above results it is concluded that volatile compounds and food preservatives can be employed in the management of fumonisins (B1)

Influence of volatile compounds on the development of off-flavours in pig back fat samples classified with boar taint by a test panel

Dynamic Head Space methodology was applied to evaluate the possible contribution of some volatile compounds to the development of boar taint in pig backfat samples with low concentrations of skatole and androstenone, but which had previously been classified as tainted by a trained test panel. Volatile compounds were collected in a trap of graphited charcoal and analysed by GC–MS in Scan mode. Aldehydes and short chain fatty acids, compounds that play a significant role in the development of undesirable aromas in food products, were the main classes of compounds identified in this study, although the possible contribution of other compounds that were detected in a minor proportion – such as alcohols and ketones – was evaluated. Styrene and 1,4-dichlorobenzene, compounds that may have come from an external contamination, showed a high concentration in the samples classified with boar taint, so these compounds could have been responsible for the development of some off-flavours in the fat samples studied in this work. In the same study, skatole and androstenone were also determined by normal phase HPLC and GCMS, respectively.

Influence of volatile compounds on virgin olive oil quality evaluated by analytical approaches and sensor panels

Volatile compounds, retained by virgin olive oils during their extraction process, are responsible for the oil aroma. Approximately one hundred and eighty compounds, whose structure was assigned by means of gas chromatography-mass spectrometry, were found in virgin olive oil aromas. The analytical approaches to their determination are briefly discussed, considering the problems related to the volatile compound collection and to adsorbents used for their trapping. The sensory methodology for the evaluation of the organoleptic characteristics of the virgin olive oils are reported and typical flavours and off-flavours are described. Compounds responsible for flavours, including factors affecting the volatile fraction, and for off-flavours are carefully examined, also considering the causes that give rise to off-flavours. Relationships between volatile compounds and sensory characteristics, found by various researchers, are reviewed.

Influence of Volatile Compounds from Alfalfa Hay on Microbial Activity in Soil in Relation to Growth of Sclerotium rolfsii

Influence of Volatile Compounds from Alfalfa Hay on Microbial Activity in Soil in Relation to Growth of Sclerotium rolfsii