Single Molecule Observations of Fatty Acid Adsorption at the Silica/Water Interface: Activation Energy of Attachment

2008 ◽  
Vol 113 (6) ◽  
pp. 2078-2081 ◽  
Author(s):  
Andrei Honciuc ◽  
Alexander L. Howard ◽  
Daniel K. Schwartz
Keyword(s):  
Activation Energy ◽  
Fatty Acid ◽  
Single Molecule ◽  
Water Interface

Metastability in Monolayer Films Transferred onto Solid Substrates by the Langmuir-Blodgett Method: IR Evidence for Transfer-Induced Phase Transitions

1994 ◽  
Vol 48 (10) ◽  
pp. 1196-1203 ◽  
Author(s):  
Fazale R. Rana ◽  
Suci Widayati ◽  
Brian W. Gregory ◽  
Richard A. Dluhy
Keyword(s):  
Fatty Acid ◽  
Conformational Changes ◽  
Structural Changes ◽  
High Surface ◽  
Solid Substrate ◽  
Water Interface ◽  
Monolayer Films ◽  
Langmuir Blodgett ◽  
Monomolecular Film ◽  
Air Water Interface

The rate at which a monomolecular film is deposited onto a solid substrate in the Langmuir-Blodgett process of preparing supported monolayer films influences the final structure of the transferred film. Attenuated total reflectance infrared spectroscopic studies of monolayers transferred to germanium substrates show that the speed at which the substrate is drawn through the air/water interface influences the final conformation in the hydrocarbon chains of amphiphilic film molecules. This transfer-induced effect is especially evident when the monolayer is transferred from the expanded region of surface-pressure-molecular-area isotherms at low surface pressures; the effect is minimized when the film molecules are transferred from condensed phases at high surface pressures. This phenomenon has been observed for both a fatty acid and a phospholipid, which suggests that these conformational changes may occur in a variety of hydrocarbon amphiphiles transferred from the air/water interface. This conformational ordering may be due to a kinetically limited phase transition taking place in the meniscus formed between the solid substrate and aqueous subphase. In addition, the results obtained for both the phospholipid and fatty acid suggest that the structure of the amphiphile may help determine the extent and nature of the transfer-speed-induced structural changes taking place in the monomolecular film.

scholarly journals Mechanistic Insights on the Photosensitized Chemistry of a Fatty Acid at the Air/Water Interface

2016 ◽  
Vol 50 (20) ◽  
pp. 11041-11048 ◽  
Author(s):  
Liselotte Tinel ◽  
Stéphanie Rossignol ◽  
Angelica Bianco ◽  
Monica Passananti ◽  
Sébastien Perrier ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Water Interface ◽  
Air Water Interface

Thermal Degradation of Complexes Derived from Cu (II) Groundnut (Arachis hypogaea) and Sesame (Sesamum indicum) Soaps

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Anju Joram ◽  
Rashmi Sharma ◽  
Arun kumar Sharma
Keyword(s):  
Activation Energy ◽  
Fatty Acid ◽  
Thermal Degradation ◽  
Arachis Hypogaea ◽  
Edible Oils ◽  
Analytical Data ◽  
Spectroscopic Technique ◽  
Sesamum Indicum ◽  
Energy Of Activation ◽  
Significant Information

Abstract The complexes have been synthesized from Cu (II) soaps of groundnut (Arachis hypogaea) and sesame (Sesamum indicum) oils, with ligand containing nitrogen and sulfur atoms like 2-amino-6-methyl benzothiazole. The complexes were greenish brown in color. In order to study TGA, first characterized them by elemental analysis, and spectroscopic technique such as IR, NMR and ESR. From the analytical data, the stoichiometry’s of the complexes have been observed to be 1:1 (metal:ligand). These complexes have been thermally analyzed using TGA techniques to determine their energy of activation. These complexes show three step thermal degradation corresponding to fatty acid components of the edible oils and each complex has three decomposition steps in the range of 439–738 K. Various equations like Coats–Redfern (CR), Horowitz–Metzger (HM) and Broido equations (BE) were applied to evaluate the energy of activation. The values of energy of activation are observed to be in the following order for both copper groundnut benzothiazole (CGB) and copper sesame benzothiazole (CSeB) complexes: CGB > CSeB. CGB is observed to be more stable than CSeB due to its higher activation energy. The above studies would provide significant information regarding the applications of synthesized agrochemicals and their safe removal through parameters obtained in degradation curves and its relation with energy.

Enabling single-molecule localization microscopy in turbid food emulsions

2021 ◽  
Author(s):  
Abbas Jabermoradi ◽  
Suyeon Yang ◽  
Martijn Gobes ◽  
John P.M. van Duynhoven ◽  
Johannes Hohlbein
Keyword(s):  
Adaptive Optics ◽  
Single Molecule ◽  
Optical Resolution ◽  
Three Dimensions ◽  
Water Interface ◽  
Water Emulsion ◽  
Food Emulsions ◽  
Localization Microscopy ◽  
Oil Water ◽  
Single Molecule Localization Microscopy

Turbidity poses a major challenge for the microscopic characterization of many food systems. In these systems, local mismatches in refractive indices can cause reflection, absorption and scattering of incoming as well as outgoing light leading to significant image deterioration along sample depth. To mitigate the issue of turbidity and to increase the achievable optical resolution, we combined adaptive optics (AO) with single-molecule localization microscopy (SMLM). Building on our previously published open hardware microscopy framework, the miCube, we first added a deformable mirror to the detection path. This element enables both the compensation of aberrations directly from single-molecule data and, by further modulating the emission wavefront, the introduction of various point spread functions (PSFs) to enable SMLM in three dimensions. We further added a top hat beam shaper to the excitation path to obtain an even illumination profile across the field of view (FOV). As a model system for a non-transparent food colloid in which imaging in depth is challenging, we designed an oil-in-water emulsion in which phosvitin, a ferric ion binding protein present in from egg yolk, resides at the oil water interface. We targeted phosvitin with fluorescently labelled primary antibodies and used PSF engineering to obtain 2D and 3D images of phosvitin covered oil droplets with sub 100 nm resolution. Droplets with radii as low as 200 nm can be discerned, which is beyond the range of conventional confocal light microscopy. Our data indicated that in the model emulsion phosvitin is homogeneously distributed at the oil-water interface. With the possibility to obtain super-resolved images in depth of nontransparent colloids, our work paves the way for localizing biomacromolecules at colloidal interfaces in heterogeneous food emulsions.

Molecular and biochemical analyses of avocado (Persea americana) reveal differences in the oil accumulation pattern between the mesocarp and seed during the fruit developmental period

2020 ◽  
Author(s):  
Yu Ge ◽  
Xiangshu Dong ◽  
Yuanzheng Liu ◽  
Ying Yang ◽  
Rulin Zhan
Keyword(s):  
Transcription Factors ◽  
Fatty Acid ◽  
Single Molecule ◽  
Oil Production ◽  
Developmental Period ◽  
Persea Americana ◽  
Oil Accumulation ◽  
Accumulation Pattern ◽  
Tissue Specific ◽  
Non Coding Rnas

Abstract Background: The avocado (Persea americana) mesocarp and seed contain high-value oil with broad industrial applications. The oil contents in these two tissues vary considerably at maturity. Additionally, the molecular mechanism underlying the tissue-specific oil accumulation in the developing avocado mesocarp and seed remains unclear, which has hampered the exploration of the utility of avocado for oil production.Results: To clarify the mechanisms mediating the differences in oil contents and fatty acid compositions, the transcriptomes and oil bodies were compared between the oil-storing tissues during the fruit developmental period. The results revealed the increasing and fluctuating trends in the oil accumulation in the developing avocado mesocarp and seed, respectively. Additionally, striking differences in the lipid droplets between the mature mesocarp and seed were revealed in confocal microscopy images. Subsequently, the gene transcription profiles of the developing mesocarp and seed were characterized via a comprehensive transcriptome analysis involving second-generation sequencing and single-molecule real-time sequencing techniques. The tissue-specific transcription of lipid-related genes contributing to fatty acid synthesis, triacylglycerol assembly, and triacylglycerol storage was examined, with most of the lipid-related genes expressed at higher levels in the developing mesocarp than in the developing seed. A weighted gene co-expression network analysis uncovered 291 transcription factors that were commonly or uniquely correlated with the oil contents in the avocado mesocarp and seed. Moreover, 11 trans-acting and 79 cis-acting long non-coding RNAs were identified as common or unique to the developing avocado mesocarp and seed. These long non-coding RNAs may regulate the expression of 43 lipid-related genes. Finally, a network of genes associated with oil accumulation in the developing avocado mesocarp and seed was established.Conclusions: The results of this study further elucidate the tissue-specific oil biosynthesis and related regulatory network in the avocado mesocarp and seed. Furthermore, tissue-specific lipid-related genes, putative transcription factors, and putativelong non-coding RNAs affecting oil accumulation were identified. Our data may also be useful for characterizing tissue-specific oil accumulation at the transcriptomic level, thereby identifying candidate genes for improving the oil production of related plant species.

Atmospheric photochemistry at a fatty acid-coated air-water interface

Science ◽  
2016 ◽  
Vol 353 (6300) ◽  
pp. 699-702 ◽  
Author(s):  
S. Rossignol ◽  
L. Tinel ◽  
A. Bianco ◽  
M. Passananti ◽  
M. Brigante ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Water Interface ◽  
Atmospheric Photochemistry ◽  
Air Water Interface
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