A fast and effective way to measure the inner pore size distributions of wetted cotton fibers and their pretreatment performance using time-domain nuclear magnetic resonance.

This study reports the findings from using time-domain nuclear magnetic resonance (TD-NMR) to analyze the pore structures of cotton fibers. Cotton fibers, which swell and soften in water, present challenges for conventional pore measurement techniques. TD-NMR overcomes these by measuring the transverse relaxation time (T2) of water protons within the fibers, indicative of internal pore sizes. We established a T2-to-pore size conversion equation using mixed cellulose ester membranes. This enabled differentiation between strongly bound, loosely bound, and free water within the fibers, and detailed the water distribution. A method for measuring the pore size distribution of wet cotton fiber was developed using TD-NMR. We then examined how various pretreatments affect the fibers' internal pores by comparing their pore size distribution and porosity. Specifically, caustic mercerization primarily enlarges the porosity and size of larger pores, while liquid ammonia treatment increases porosity but reduces the size of smaller pores. This research confirms TD-NMR's utility in assessing cotton fabrics' wet processing performance.

Designing Sustainable Hydrophilic Interfaces via Feature Selection from Molecular Descriptors and Time-Domain Nuclear Magnetic Resonance Relaxation Curves.

Surface modification using hydrophilic polymer coatings is a sustainable approach for preventing membrane clogging due to foulant adhesion to water treatment membranes and reducing membrane-replacement frequency. Typically, both molecular descriptors and time-domain nuclear magnetic resonance (TD-NMR) data, which reveal physicochemical properties and polymer-chain dynamics, respectively, are required to predict the properties and understand the mechanisms of hydrophilic polymer coatings. However, studies on the selection of essential components from high-dimensional data and their application to the prediction of surface properties are scarce. Therefore, we developed a method for selecting features from combined high-dimensional molecular descriptors and TD-NMR data. The molecular descriptors of the monomers present in polyethylene terephthalate films were calculated using RDKit, an open-source chemoinformatics toolkit, and TD-NMR spectroscopy was performed over a wide time range using five-pulse sequences to investigate the mobility of the polymer chains. The model that analyzed the data using the random forest algorithm, after reducing the features using gradient boosting machine-based recursive feature elimination, achieved the highest prediction accuracy. The proposed method enables the extraction of important elements from both descriptors of surface properties and can contribute to the development of new sustainable materials and material-specific informatics methodologies encompassing multiple information modalities.

Water properties in intact wooden breast fillets during refrigerated storage.

The wooden breast (WB) condition notably alters moisture content and water holding capacity (WHC) in broiler breast fillets. The purpose of this study was to investigate water properties during refrigerated storage from 4 h to 168 h postmortem using time domain nuclear magnetic resonance (TD-NMR). Water properties measured included mobility (T), proportion (P), and abundance per 100 g of meat (A). Changes in meat quality indicators including compression force, color, pH, cumulative purge loss, and proximate composition were also measured. Compression force and energy of the WB fillets were higher than normal fillets (P < 0.05). Slopes of changes in lightness of the WB and normal fillets were different in skin and bone side (P < 0.05). The slope of the purge loss from the WB fillets was higher than the normal fillets (P < 0.05). Time domain nuclear magnetic resonance analysis showed 4 water populations in intact broiler fillets with transverse relaxation time (T2) constants at approximately 4 to 5 milliseconds (ms) (designated as 2b, corresponding to hydration water or bound water), 40 to 60 ms (designated as 21, corresponding to intra-myofibrillar water or immobilized water), 80 to 210 ms (designated as 22a, corresponding to extra-myofibrillar water or free water with lower mobility) and 210 to 500 ms (designated as 22b, corresponding to extra-myofibrillar water or free water with higher mobility) during early postmortem storage (between 4 h and 72 h postmortem) and only 3 populations (2b, 21, and 22a) after 72 h postmortem. There were interaction effects (P < 0.05) between storage time and WB condition for all water properties except T2b, A2b/100 g, and T22b. The linear change of T21, P21, A21/100 g, T22a, A22a/100 g, P22b, and A22b/100 g in stored WB samples were different from the normal fillets (P < 0.05). During storage, P21 and A21/100 g of the WB fillets exhibited faster linear increases than those of the normal fillets, whereas T21 and T22a of the normal fillets and A22a/100 g, P22b, and A22b/100 g of the WB fillets showed faster linear decreases (P < 0.05). Our data demonstrate that the WB condition affects changes in water properties in broiler fillets during postmortem refrigerated storage.

Magnetic resonance quantification of skeletal muscle lipid infiltration in a humanized mouse model of Duchenne muscular dystrophy.

Rodent models of Duchenne muscular dystrophy (DMD) often do not recapitulate the severity of muscle wasting and resultant fibro-fatty infiltration observed in DMD patients. Having recently documented severe muscle wasting and fatty deposition in two preclinical models of muscular dystrophy (Dysferlin-null and mdx mice) through apolipoprotein E (ApoE) gene deletion without and with cholesterol-, triglyceride-rich Western diet supplementation, we sought to determine whether magnetic resonance imaging and spectroscopy (MRI and MRS, respectively) could be used to detect, characterize, and compare lipid deposition in mdx-ApoE knockout with mdx mice in a diet-dependent manner. MRI revealed that both mdx and mdx-ApoE mice exhibited elevated proton relaxation time constants (T2 ) in their lower hindlimbs irrespective of diet, indicating both chronic muscle damage and fatty tissue deposition. The mdx-ApoE mice on a Western diet (mdx-ApoEW ) presented with greatest fatty tissue infiltration in the posterior compartment of the hindlimb compared with other groups, as detected by MRI/MRS. High-resolution magic angle spinning confirmed elevated lipid deposition in the posterior compartments of mdx-ApoEW mice in vivo and ex vivo, respectively. In conclusion, the mdx-ApoEW model recapitulates some of the extreme fatty tissue deposition observed clinically in DMD muscle but typically absent in mdx mice. This preclinical model will help facilitate the development of new imaging modalities directly relevant to the image contrast generated in DMD, and help to refine MR-based biomarkers and their relationship to tissue structure and disease progression.

Application of time domain nuclear magnetic resonance (TD-NMR) for study of the distillation curve of petroleum.

Crude oil distillates are a highly useful industrial product, mainly for energy generation. Unfortunately, they are rarely studied, mainly due to the low accessibility to products directly obtained from the distillation process, which is a laborious, expensive, and time-consuming operation. This work presents and discusses the use of time-domain nuclear magnetic resonance (TD-NMR) as a simple, affordable, and straightforward tool for the development of correlations supported on the transverse relaxation time (T2 ) and boiling temperature. The results point out a high convergence between TD-NMR experimental data and the ASTM D2892 method for distillates from light, medium, and heavy oils, with up to 52.20% of accumulated mass and boiling point temperature (Tb ) up to 400°C. Furthermore, an unprecedented relationship between T2 values and the accumulated mass of the distillates is first demonstrated. This new insight opens new perspectives for future prediction of accumulated mass for unknown crude oils, placing the TD-NMR relaxometry as an appeal spectroscopy approach with a potential to meaningfully contribute to the daily refining petrochemical industry field operations.

Nanodiamond (ND)-based polyamide (PA) 66 nanocomposite studied with infrared (IR) microscopy and time-domain nuclear magnetic resonance (TD-NMR) combined with two-trace two-dimensional (2T2D) correlation analysis.

Nanodiamond/polyamide (ND/PA) nanocomposite was examined with infrared (IR) microscopy and time-domain nuclear magnetic resonance (TD-NMR) to elucidate in detail the interphase between amino functionalized ND (ND-NH2) and PA 66. An IR image of the ND/PA nanocomposite suggested the uniform nanoscale distribution of the ND-NH2 particles thanks to the spherical shape and accessible external surface of ND terminated with reactive amino groups. On the other hand, a substantial level of change was observed in T2 decay curves when the ND-NH2 particles were incorporated in the PA 66. The fine features of the thermally induced changes in the decay curves were readily analyzed with the two-trace two-dimensional (2T2D) correlation method. The variation in the asynchronous correlation intensity indicated that the changes observed in the mechanical properties of the ND/NH2 may be attributed to the development of crosslinking between tie chains in the amorphous region via the interaction between the ND-NH2 and PA 66. Accordingly, such firm links have a substantial effect in preventing the displacement of the amorphous domain, which eventually increases the Young's modulus but reduces the ductility of the PA.

Quantifying water distribution between starch and protein in doughs and gels from mildly refined faba bean fractions.

The development of novel and sustainable food products, such as cheese- and meat analogues, requires a better understanding of the use of less refined ingredients. We investigated the distribution of water between the protein and starch phase of doughs and heat-induced gels made from air-classified faba bean fractions by developing a method suited for investigation of such multi-component ingredients. The moisture contents of the protein and starch phases in the dough were determined using a method based on partial sorption isotherms of mixed doughs of protein- and starch-rich fractions at high water activity. Water content of the protein phase is higher than that of the starch phase in dough, showing that protein takes up more water than starch at room temperature. Also, the moisture content of the protein phase in the gels was calculated using a model based on the denaturation temperature of legumin. From the experiments and the modelling, it became evident that the moisture content of the protein phase in the gel is lower than the moisture content of the protein phase in the dough, showing the importance of considering moisture migration from the protein to the starch during heating.

Untargeted analysis of TD-NMR signals using a multivariate curve resolution approach: Application to the water-imbibition kinetics of Arabidopsis seeds.

The aim of this study is to investigate the ability of Time-Domain Nuclear Magnetic Resonance (TD-NMR) combined with Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) analysis to detect changes in hydration properties of nineteen genotypes of Arabidopsis (Arabidopsis thaliana) seeds during the imbibition process. The Hybrid hard and Soft modelling version of MCR-ALS (HS-MCR) applied to raw TD-NMR data allowed the introduction of kinetic models to elucidate underlying biological mechanisms. The imbibition process of all investigated hydrated Arabidopsis seeds could be described with a kinetic model based on two consecutive first-order reactions related to an initial absorption of water from the bulk around the seed and a posteriori hydration of the internal seed tissues, respectively. Good data fit was achieved (LOF % = 0.98 and r2% = 99.9), indicating that the hypothesis of the selected kinetic model was correct. An interpretation of the mucilage characteristics of the studied Arabidopsis seeds was also provided. The presented methodology offers a novel and general strategy to describe in a comprehensive way the kinetic process of plant tissue hydration in a screening objective. This work also proves the potential of the MCR methods to analyse raw TD-NMR signals as alternative to the controversial and time-consuming pre-processing techniques of this kind of data, known to be an ill-conditioned and ill-posed problem.

Smoothing temperature and ratio of casein to whey protein: Two tools to improve nonfat stirred yogurt properties.

Consumers are not always ready to compromise on the loss of texture and increased syneresis that nonfat stirred yogurts display compared with yogurts that contain fat. In this study, we investigated milk protein composition and smoothing temperature as a means to control nonfat yogurt microstructure, textural properties, and syneresis. Yogurts were prepared with different ratios of casein to whey protein (R1.5, R2.8, and R3.9). Yogurts were pumped through a smoothing pilot system comprising a plate heat exchanger set at 15, 20, or 25°C and then stored at 4°C until analysis (d 1, 9, and 23). Yogurt particle size and firmness were measured. Yogurt syneresis and water mobility were determined, respectively, by centrifugation and time domain low-frequency proton nuclear magnetic resonance (1H-LF-NMR). Increasing the smoothing temperature increased gel firmness and microgel (dense protein aggregates) sizes independently of the whey protein content. Also, yogurt microgel sizes changed with storage time, but the evolution pattern depended on protein ratio. Yogurt R1.5 showed the largest particles, and their sizes increased with storage, whereas R2.8 and R3.9 had smaller microgels, and R3.9 did not show any increase in microgel size during storage. Micrographs showed a heterogeneous gel with the empty area occupied by serum for R1.5, whereas R2.8 and R3.9 showed fewer serum zones and a more disrupted gel embedding microgels. Induced syneresis reduced with greater whey protein content and time of storage. This is in agreement with 1H-LF-NMR showing less bulk water mobility with increasing whey protein content during storage. However, 1H-LF-RMN revealed higher values of spontaneous serum separation during storage for R1.5 and R3.9 yogurts, whereas these were lower and stable for R2.8 yogurt. Microgels play an important structural role in yogurt textural attributes, and their characteristics are modulated by whey protein content and smoothing temperature. Optimization of these parameters may help improve nonfat stirred dairy gel.

Impact of chemical exchange on transverse relaxation at low and moderate magnetic field strengths for sugar solutions representative of fruit tissues analyzed by simulation and MRI experiments.

Proton exchange effects on transverse relaxation rate were studied at low and moderate magnetic fields. Analysis was conducted on low-concentrate simple sugar (fructose and glucose) solutions modeling the vacuolar liquid in fruits. Simulated data obtained from Carver and Richards equations were used to analyze the effects of temperature and pH on parameters involved in the chemical exchange mechanisms. The results have highlighted that measurement conditions and tissue characteristics (echo time, magnetic field strength, temperature, pH, etc.) significantly impact the transverse relaxation rate via chemical exchange, even for low and mid magnetic fields and the narrow echo time ranges of TD-NMR and MRI measurements. This explains some of the divergent relaxation data from plant tissue NMR measurements reported in the literature and emphasizes the importance of taking experimental conditions and tissue characteristics into account when interpreting results. It also clearly demonstrates that the appropriate choice of experimental conditions can emphasize the effects of sugar concentration or pH variations on transverse relaxation in vacuolar liquids, making it possible to monitor these parameters accurately via transverse relaxation measurements. The impact of concentration, solute type, pH and temperature on transverse relaxation of sugar solutions were demonstrated experimentally at 1.5 T with an MRI scanner. These data were interpreted using the Carver-Richards model which was effective in estimating parameters involved in chemical exchange mechanism in the imaging experiment.

Molecular mobility changes after high-temperature, short-time pasteurization: An extended time-domain nuclear magnetic resonance screening of ewe milk.

This study presents an extensive investigation on the effect of pasteurization on raw whole ewe milk. Milk samples have been analyzed, throughout lactation (from February to July), by time-domain nuclear magnetic resonance (TD-NMR), collecting the characteristic TD-NMR relaxation parameters, proton longitudinal and transverse relaxation times (1H T1 and T2). Collected data aim at integrating previous NMR works, mainly focusing on dairy model systems (casein and whey proteins solutions and gels, reconstituted skim milk) and cheese, with specific reference to the effect of heat treatments. Whole ewe milk, from a single flock (Sarda sheep breed), was daily analyzed both as untreated (raw) and heat treated with a laboratory-scaled high-temperature, short-time treatment (72°C for 15 and 20 s). Moreover, molecular dynamics in milk were investigated by TD-NMR in different periods of lactation for the first time. As a consequence of high-temperature short-time treatment, 1H T1 and T2 consistently shifted to lower values with respect to raw counterparts. Statistical analysis indicated a significant decrease of T2 in treated samples, to an extent dependent on the heat treatment duration. A subset of dedicated experiments demonstrated that the observed T2 shift is largely ascribable to protein molecular rearrangements and, to a lesser extent, to the interaction of fat globules with proteins or other nonfat components (or both). In light of the crucial importance of detecting the application of a heat treatment to milk, the results reported here suggest TD-NMR relaxation parameters were able to describe heat-induced changes in molecular dynamics and interactions of milk components in a water-rich environment. The use of TD-NMR can be considered a potential suitable technique for quality control and assurance practices in the dairy industry. Upon statistical validation of methods, the application of TD-NMR in the dairy industry would take advantage of its low cost, reliability, and robustness.

Effect of the molecular mobility of water adsorbed by disintegrants on storage-induced hydrolytic degradation of acetylsalicylic acid incorporated into tablets under humid conditions.

The purpose of this study was to investigate the effect of molecular mobility of water adsorbed by disintegrants on the hydrolytic degradation of active pharmaceutical ingredients (APIs). Fourteen different disintegrants were tested. First, powdered disintegrants were stored at conditions of 40 °C/75% relative humidity ("humid conditions") and their T2 relaxation times were measured by time-domain nuclear magnetic resonance for examination of the molecular mobility of water adsorbed by the disintegrant. From the observed T2 values, the water molecular mobility was fully characterized. In particular, the molecular mobility of water adsorbed by crospovidones was much higher than the molecular mobility of water adsorbed by the other test disintegrants because of longer T2 values. The next study examined the hydrolytic degradation of acetylsalicylic acid (ASA), a model moisture-sensitive API, stored under humid conditions. Physical mixtures of ASA and disintegrants or their model tablets were used as test samples, and they were stored for 7 d. The disintegrants contained in the samples clearly affected the ASA degradation: the most significant ASA degradation was observed for the crospovidone-containing samples. Finally, we analyzed the effect of the molecular mobility of water adsorbed by disintegrants on the ASA degradation by the least absolute shrinkage and selection operator (Lasso) regression techniques. As in the T2 experiment, various properties of disintegrants (i.e., water content, pH, and water activity) were used in this experiment as the explanatory variables. From the Lasso analysis, we successfully showed that the higher molecular mobility of water adsorbed by disintegrants significantly enhanced ASA degradation. These findings provide profound insights into the chemical stability of moisture-sensitive APIs in tablets.

Investigation of water state during induced crystallization of honey.

This work studied water state of honey during crystallization, obtained statically and dynamically, by differential scanning calorimetry (DSC), water activity (aw) assessment and time domain nuclear magnetic resonance (TD-NMR). Crystallization was induced by adding 5% of crystallized honey to three honey samples with different fructose/glucose ratio, the key characteristic for honey crystallization. Samples were stored at 14 °C. Dynamic crystallization was obtained by using an impeller. DSC showed that the dynamic crystallization was faster than the static one, the latter characterized by two phases, showing different rates. The crystallization rate did not affect aw, that remained below 0.600. TD-NMR allowed to separately observe two kinds of protons, both pertaining to liquid sugars, one chemically exchanging with water and one not exchanging with it. The combination of techniques allowed speculating that the two crystallization methods led to crystals of different size and shape.

Whey acerola-flavoured drink submitted Ohmic Heating: Bioactive compounds, antioxidant capacity, thermal behavior, water mobility, fatty acid profile and volatile compounds.

Whey acerola-flavoured drink was subjected to Ohmic Heating (OH) under different operational conditions (45, 60, 80 V at 60 Hz and 10, 100, 1000 Hz with 25 V, 65 °C/30 min) and conventional pasteurization (65 °C/30 min). Bioactive compounds (total phenolics, DPPH, FRAP, ACE levels), fatty acid profile, volatile compounds (CG-MS), thermal behaviors (DSC) and water mobility (TD-NMR) were performed. Reduction of frequency (1000-10 Hz) resulted in a lower bioactive compounds and antioxidant capacity of the samples, except for the DPPH values. Concerning the thermal behaviors, fatty acids profile and volatile compounds, different findings were observed as a function of the parameters used (voltage and frequency). In respect of TD-NMR parameters, OH led to a slightly reduction of the relaxation time when compared to the conventional treatment, suggesting more viscous beverages. Overall, OH may be interesting option to whey acerola-flavoured drink processing.

The impact of pulsed electric fields and ultrasound on water distribution and loss in mushrooms stalks.

Pulsed electric fields (PEF) and ultrasound (US) are promising innovative technologies with the potential to increase mass transfer when combined with further processes which in turn can provide potential benefits in the recovery of valuable compounds from food by-products. To provide evidence of the mechanism of mass transfer enhancement, the present study assessed the impact of PEF and US treatments, applied individually and in combination, at low and high temperatures, on the tissue microstructure of mushroom stalks. Different indices such as quantitative water redistribution, water loss and qualitative release of compounds were evaluated. The combination of these physical methods demonstrated that PEF redistributed a greater proportion of intracellular water into extracellular spaces than US. However, the application of high temperature treatments alone showed an even greater proportion of intracellular water migration compared to PEF. When PEF was combined with US at low temperatures the difference was not significant.

Advanced characterisation of encapsulated lipid powders regarding microstructure by time domain-nuclear magnetic resonance.

Encapsulation is an established technique to protect sensitive materials from environmental stress. In order to understand the physical protection mechanism against oxidation, knowledge about the powder microstructure is required. Time domain-nuclear magnetic resonance (TD-NMR) has the potential to determine the surface oil (SO) and droplet size distribution by relaxation and restricted self-diffusion, respectively. The amount of SO, the retention and encapsulation efficiency are determined based on a lipid balance. The oil load of the initial powder and after SO removal is measured by TD-NMR. The results correlate with gravimetric and photometric references. The oil droplet size obtained by TD-NMR correlates well with static light scattering. The diameter of droplets in emulsions and dried powder both measured by TD-NMR, correlates (r = 0.998), implying that oil droplets embedded in a solid matrix can be measured. Summarising, TD-NMR allows analysis of the microstructure of encapsulated lipid powders, in a rapid, simple and non-destructive way.

Assessing the effects of different prebiotic dietary oligosaccharides in sheep milk ice cream.

The objective of this study was to assess the effects of different prebiotic dietary oligosaccharides (inulin, fructo-oligosaccharide, galacto-oligossacaride, short-chain fructo-oligosaccharide, resistant starch, corn dietary oligosaccharide and polydextrose) in non-fat sheep milk ice cream processing through physical parameters, water mobility and thermal analysis. Overall, the fat replacement by dietary prebiotic oligosaccharides significantly decreased the melting time, melting temperature and the fraction and relaxation time for fat and bound water (T22) while increased the white intensity and glass transition temperature. The replacement of sheep milk fat by prebiotics in sheep milk ice cream constitutes an interesting option to enhance nutritional aspects and develop a functional food.

A novel noninvasive procedure for high-throughput screening of major seed traits.

The large numbers of samples processed in breeding and biodiversity programmes require the development of efficient methods for the nondestructive evaluation of basic seed properties. Near-infrared spectroscopy is the state-of-the-art solution for this analytical demand, but it also has some limitations. Here, we present a novel, rapid, accurate procedure based on time domain-nuclear magnetic resonance (TD-NMR), designed to simultaneously quantify a number of basic seed traits without any seed destruction. Using a low-field, benchtop (1) H-NMR instrument, the procedure gives a high-accuracy measurement of oil content (R(2) = 0.98), carbohydrate content (R(2) = 0.99), water content (R(2) = 0.98) and both fresh and dry weight of seeds/grains (R(2) = 0.99). The method requires a minimum of ~20 mg biomass per sample and thus enables to screen individual, intact seeds. When combined with an automated sample delivery system, a throughput of ~1400 samples per day is achievable. The procedure has been trialled as a proof of concept on cereal grains (collection of ~3000 accessions of Avena spp. curated at the IPK genebank). A mathematical multitrait selection approach has been designed to simplify the selection of outlying (most contrasting) accessions. To provide deeper insights into storage oil topology, some oat accessions were further analysed by three-dimensional seed modelling and lipid imaging. We conclude that the novel TD-NMR-based screening tool opens perspectives for breeding and plant biology in general.