Water/moisture and fat analysis by time-domain NMR

Todt, Harald; Guthausen, Gisela; Burk, Wolfgang; Schmalbein, Dieter; Kamlowski, A.

doi:10.1016/j.foodchem.2005.04.032

Cited by 137 publications

(63 citation statements)

References 3 publications

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“…The sample is a full fat milk powder which involve protein, lactose and fat, where fat has a comparable molecular size as the protein. As these component increased in volume (by virtue of the concentration increase), the nucleus rotation will be slower and this causes a faster decay of the relaxation time [9,11]. Figure 2 demonstrates the changes in the image contrast due to the changes in the inversion time (Ti) applied and the different milk concentration on each part of the letters (NTU) using the spine coil.…”

Section: Resultsmentioning

confidence: 99%

“…It has been previously shown that the water self-diffusion in dairy products depends on the amount of the protein, lactose and fat in the sample which also affect the relaxation times [8,9]. In this work we report the use of solutions comprising of full fat milk powder as a safe and inexpensive material that can affect the longitudinal relaxation time over a wide range of values and give a set of samples which are easily replicated in any setting.…”

Section: Introductionmentioning

confidence: 98%

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Novel Food-Safe Spin-Lattice Relaxation Time Calibration Samples for Use in Magnetic Resonance Sensor Development

Almazrouei

Newton

Dye

et al. 2017

The 4th International Electronic Conference on Sensors and Applications

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Magnetic Resonance (MR) sensors are an area of increasing interest for the measurement and monitoring of material properties. There are two relaxation times associated with samples that can be measured with MR sensors: The spin-lattice and spin-spin relaxations. When developing new sensors, it is desirable to have a series of standards by which instruments can be assessed. The standard calibration materials available typically comprise different concentrations of Nickel Sulphate which is carcinogenic and toxic. In this work we report the use of solutions containing full fat milk powder as a safe and inexpensive material that shortens the longitudinal relaxation time of water over a wide range of values. We demonstrate that concentrations in distilled water from 5% w/v to 64% w/v give T1 values from 1.7 s down to 469 ms respectively in a 1.5T clinical MRI, while within an MR sensor these times were from 1.6 s down to 431 ms. In addition, both systems have the same exponential coefficient (−0.022× concentration) that demonstrates the effectiveness of the NMR sensor in comparison to the clinical MRI.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Novel Food-Safe Spin-Lattice Relaxation Time Calibration Samples for Use in Magnetic Resonance Sensor Development

Almazrouei

Newton

Dye

et al. 2017

The 4th International Electronic Conference on Sensors and Applications

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“…For total fatty acid analysis, a portion of each extract was transesterified in methanolic HCl and the purified methyl esters were quantified against a heptadecanoic acid internal standard by gas chromatography-flame ionization detector (26). Seed oil content was quantified by time-domain 1 H-NMR (45). All solvents were Optima grade from Thermo-Fisher Scientific.…”

Section: Methodsmentioning

confidence: 99%

Disruption of theArabidopsisCGI-58 homologue produces Chanarin–Dorfman-like lipid droplet accumulation in plants

James

Horn

Case

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

131

124

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CGI-58 is the defective gene in the human neutral lipid storage disease called Chanarin-Dorfman syndrome. This disorder causes intracellular lipid droplets to accumulate in nonadipose tissues, such as skin and blood cells. Here, disruption of the homologous CGI-58 gene in Arabidopsis thaliana resulted in the accumulation of neutral lipid droplets in mature leaves. Mass spectroscopy of isolated lipid droplets from cgi-58 loss-of-function mutants showed they contain triacylglycerols with common leaf-specific fatty acids. Leaves of mature cgi-58 plants exhibited a marked increase in absolute triacylglycerol levels, more than 10-fold higher than in wild-type plants. Lipid levels in the oil-storing seeds of cgi-58 loss-of-function plants were unchanged, and unlike mutations in β-oxidation, the cgi-58 seeds germinated and grew normally, requiring no rescue with sucrose. We conclude that the participation of CGI-58 in neutral lipid homeostasis of nonfat-storing tissues is similar, although not identical, between plant and animal species. This unique insight may have implications for designing a new generation of technologies that enhance the neutral lipid content and composition of crop plants.compartmentation | plant lipid metabolism P lants synthesize and store neutral lipids such as triacylglycerols (TAGs) primarily in cytosolic lipid droplets of maturing seeds (1, 2). In domesticated oilseeds, these stored TAGs represent a major source of calories for human and animal nutrition, an excellent feedstock for diesel fuels, and a reservoir for the deposition of industrially important fatty acids used as chemical feedstocks (3-6). Although not commonly appreciated, TAGs also are synthesized in nonseed tissues (7,8), but their abundance in these tissues is low, in part because of the metabolism of the cell and perhaps as a consequence of the continuous recycling of fatty acids for energy and membrane synthesis. Indeed, vegetative cells can incorporate radiolabeled precursors into TAG (7, 8), they express diacylglycerol acyltransferases [the only enzyme in the "Kennedy pathway" unique to TAG production (9)], and they can accumulate TAGs in β-oxidation mutants (2) and in some floral (10) and fruit (7) tissues. Thus, although plant vegetative cells appear to have the metabolic machinery to synthesize and accumulate neutral lipids, there are likely underlying regulatory mechanisms in place to minimize this process, none of which are understood.Chanarin-Dorfman syndrome is a neutral-lipid storage disease (11) caused by a defect in the protein CGI-58 (comparative gene identification-58, also called ABHD5 for α/β hydrolase-5). CGI-58 is a soluble enzyme that associates with cytosolic lipid droplets under certain metabolic conditions and appears to play a role in hydrolysis of stored lipids (11)(12)(13)(14). Several different mutations in this protein, including amino acid substitutions, premature stop codons, and defects in mRNA splicing, have been identified in various Chanarin-Dorfman patients, all of which result in a hyperac...

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“…Water and lipid content were manipulated since their protons possess longer relaxation times compared to the protons of proteins, 21,22 making it easier to detect with CPMG and the resulting T2 range of 0.2-1000 ms.…”

Section: Identification Of Yolk Componentsmentioning

confidence: 99%

Determination of the Gelation Mechanism of Freeze–Thawed Hen Egg Yolk

Acevedo

Horner

et al. 2015

J. Agric. Food Chem.

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A study of yolks stored up to 168 d at −20 °C was conducted to determine the gelation behavior and mechanism of freeze–thawed yolk. Methods used were rheology, native and sodium dodecyl sulfate polyacrylamide gel electrophoresis (native- and SDS-PAGE), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), particle size analysis, and proton nuclear magnetic resonance (1H NMR) spectroscopy for matrix mobility. Results indicate that both constituents of plasma and granules contributed to gelation of yolk under freezing. PAGE analyses suggest that granular proteins participated in aggregation during freeze–thaw. Increasing gel strength and particle size and decreasing water and lipid–water mobility indicate that lipoproteins or apolipoproteins aggregated. At storage times ≥84 d, increased protein and lipid mobility, the detection of smaller particles, and secondarily increased gel strength suggest the liberation of protein or lipoprotein components from previously formed aggregates and further aggregation of these constituents. Disruption of the gelled yolk matrix observed with TEM supported that ice crystal formation was required for gelation to occur. A two-stage dynamic gelation model is thus proposed.

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Water/moisture and fat analysis by time-domain NMR

Cited by 137 publications

References 3 publications

Novel Food-Safe Spin-Lattice Relaxation Time Calibration Samples for Use in Magnetic Resonance Sensor Development

Novel Food-Safe Spin-Lattice Relaxation Time Calibration Samples for Use in Magnetic Resonance Sensor Development

Disruption of theArabidopsisCGI-58 homologue produces Chanarin–Dorfman-like lipid droplet accumulation in plants

Determination of the Gelation Mechanism of Freeze–Thawed Hen Egg Yolk

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