We present new NMR techniques to characterize food products that are based on the measurement of two-dimensional diffusion-T2 relaxation and T1-T2 relaxation distribution functions. These measurements can be performed in magnets of modest strength and low homogeneity and do not require pulsed gradients. As an illustration, we present measurements on a range of dairy products that include milks, yogurt, cream, and cheeses. The two-dimensional distribution functions generally exhibit two distinct components that correspond to the aqueous phase and the liquid fat content. The aqueous phase exhibits a relatively sharp peak, characterized by a large T1/T2 ratio of around 4. The diffusion coefficient and relaxation times are reduced from the values for bulk water by an amount that is sample specific. The fat signal has a similar signature in all samples. It is characterized by a wide T2 distribution and a diffusion coefficient of 10(-11) m2/s for a diffusion time of 40 ms, determined by bounded diffusion in the fat globules of 3 microm diameter.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jcis.2005.10.047 | DOI Listing |
J Exp Biol
January 2025
Laboratory of Function and Evolutionary Morphology, FOCUS, Université de Liège, Liège, Belgique.
The inner ear of teleost fishes is known to serve both auditory and vestibular functions. Many studies have compared otoliths from different species and attempted to understand the observed differences within the light of environmental factors. However, experimental data on how otoliths could adapt are scarce.
View Article and Find Full Text PDFActa Crystallogr A Found Adv
March 2025
Pennsylvania State University, University Park, PA 16802, USA.
X-ray diffraction is ideal for probing the sub-surface state during complex or rapid thermomechanical loading of crystalline materials. However, challenges arise as the size of diffraction volumes increases due to spatial broadening and because of the inability to deconvolute the effects of different lattice deformation mechanisms. Here, we present a novel approach that uses combinations of physics-based modeling and machine learning to deconvolve thermal and mechanical elastic strains for diffraction data analysis.
View Article and Find Full Text PDFBiodivers Data J
January 2025
IUCN SSC Monitoring Specialist Group, Angra do Heroísmo, Azores, Portugal IUCN SSC Monitoring Specialist Group Angra do Heroísmo, Azores Portugal.
Background: Azorean biodiversity is relatively well-known following important scientific contributions during the last three decades. These have set a comprehensive species checklist for the Archipelago, improved significantly the knowledge on species abundance, ecology and distribution and have contributed to define priorities for conservation management and scientific research. Nevertheless, despite these efforts, a key functional group - the pollinators - remains poorly known in Azores, including their occurrence in different habitat-types and islands.
View Article and Find Full Text PDFJACS Au
January 2025
Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zurich, Switzerland.
Hydrogenation of CO to methanol is foreseen as a key step to close the carbon cycle. In this study, we show that introducing Ga into silica-supported nanoparticles based on group 8-9 transition noble metals (M = Ru, Os, Rh, and Ir - Ga@SiO) switches their reactivity from producing mostly methane (sel. > 97%) to producing methanol (>50% CHOH/DME sel.
View Article and Find Full Text PDFJACS Au
January 2025
Department of Cell and Molecular Biology, Uppsala University, 751 24 Uppsala, Sweden.
Disordered regions are an important functional feature of many multidomain proteins. A prime example is proteins in membraneless organelles, which contain folded domains that engage in specific interactions and disordered low-complexity (LC) domains that mediate liquid-liquid phase separation. Studying these complex architectures remains challenging due to their conformational variability.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!