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The effect of chopping time and heating on physicochemical properties of meat batters was investigated by low-field nuclear magnetic resonance and rheology technology. Cooking loss and L* increased while texture profile analysis index decreased between chopping 5 and 6 min. The relaxation time T 21 (bound water) and its peak area ratio decreased, while the ratio of T 22 peak area (immobilized water) in raw meat batters gradually increased with the extension of chopping time. However, T 22 was opposite after being heated and a new component T 23 (free water) appeared (T 2i is the spin - spin relaxation time for the ith component.). The initial damping factor (Tan δ) gradually decreased and there were significant difference between 4 and 5 min of chopping time. There were significantly positive correlations between the ratio of peak area of T 22 and chopping time, the storage modulus (G'), cooking loss, and L*, respectively. Continued chopping time could improve the peak area proportion of T 22 in raw meat batters. Further, the higher the peak area proportion of T 22 in raw meat batters, the cooking loss of heated meat gel was higher. Also, the stronger the mobility of immobilized water in meat batter, the higher the L* of the fresh meat batters. Thus, it is revealed that the physicochemical properties of meat batter are significantly influenced by chopping time which further affects the water holding capacity and the texture of emulsification gel., (© 2017 Japanese Society of Animal Science.)

The solidification of wheat dough is induced by a complex sequence of polymer transition processes. The extend of the polymer transitions is thereby strongly dependent on the hydration level of each constituent. Further, yeast metabolites, resulting from the fermentation of dough, are hypothesized to impact the functionality of dough's polymers in their thermal transitional behavior. Hence, the aim of this work was to elucidate the occurrence of polymer transitions in dependency of (i) the amount of water available for hydration and (ii) the presence of yeast metabolites. An approach of reduced complexity was chosen to reveal the interactions during the hydrothermal treatment by multiwave SAOS rheology together with basic physicochemical characterization methods (DSC, 1H NMR). By excluding single dough polymers from the solidification cascade, their functionality in the polymeric system was elucidated. In combination with a non-invasive yeast inactivation method, sophisticated information on the dependence of the matrix solidification on the matrix hydration level and presence of yeast metabolites were established. Water shortage was shown to limit the extend of starch gelatinization, resulting in a reduced overall matrix solidification, whereas the extend of gluten polymerization was not affected by water shortage. In contrast, a water surplus favored the progression of starch gelatinization, which was also shown to be induced indirectly by yeast metabolites. Therefore, the water availability and accessibility of starch were shown to be decisive for the solidification of the dough matrix. The knowledge obtained contributes to the elucidation of the impact of baker's yeast on the dough matrix. [Display omitted] • Artificial re-engineered starch–gluten systems favor progression of gelatinization • Water shortage more restrictive for gelatinization than for gluten polymerization • Increasing hydration enables more short range interaction during the baking process • Destabilizing effects of yeast metabolites likely based in gluten microstructure • Underdeveloped dough systems less impaired by degradation by yeast metabolites [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate how liquid fish oil and microencapsulated oil additives influenced the rheological characteristics and the dynamics of water binding in vacuum-packed (VP) and modified-atmosphere-packed (MAP) poultry sausages during 21-day storage. In contrast to the control sample, the sausages enriched with microencapsulated fish oil (MC) were characterised by the greatest ability to accumulate deformation energy. The elastic properties of all sausage variants increased significantly in the subsequent storage periods, whereas the dynamic viscosity of the samples tended to decrease. This phenomenon was confirmed by the gradual reduction of water activity (Aw) in all sausages in the subsequent storage periods. The packaging method influenced the dynamics of water binding in an oil-additive-form-dependent manner. During the storage of the VP and MAP sausages, in samples with the fish oil additive the T1 value tended to increase while the Aw decreased. The T1 value in the MAP MC sample was similar. The FO additive resulted in greater mobility of both proton fractions in the MAP samples than in the VP samples. There were inverse relationships observed in the MC samples. The NMR tests showed that the VP samples with the MC additive were slightly better quality than the other samples. [ABSTRACT FROM AUTHOR]

Sweet potato is one of cheap sources for starch industries worldwide, and exploiting starch wastewater as an alternative protein source is mainly environmental and economic concerns. In this study, the effects of high hydrostatic pressure (HHP; 250, 400, and 550 MPa) on chemical forces, structure, and gelation properties of sweet potato protein (SPP) at pH 3.0, 6.0, and 9.0 were investigated. The values of surface hydrophobicity (Ho) and absolute value of zeta potential of SPP significantly increased from 250 to 550 MPa (p < 0.05) at all three pH conditions. The total amount of sulfhydryl (-SH-) groups in SPP decreased after HHP at pH 9.0, whereas the amount of free -SH- increased. High molecular mass aggregates (> 180 kDa) were observed in SPP after HHP at pH 6.0 and 9.0 by SDS-PAGE. Regarding elastic rheological behaviors, storage modulus (G′) values of SPP were significantly strengthened after HHP treatment. In addition, textural properties and water-holding capacity of gels made from SPP after 250 and 400 MPa at pH 9.0 were significantly improved, and the gels showed a compact and uniform gel network with the contribution of immobilized water fractions. The gel properties exhibited by SPP after HHP treatment at different pH levels, in particular after 400 MPa at pH 9.0, suggested that it could be potential protein resources as new gelling reagent in the food system. [ABSTRACT FROM AUTHOR]

Abstract: The effect of chopping time and heating on physicochemical properties of meat batters was investigated by low‐field nuclear magnetic resonance and rheology technology. Cooking loss and L* increased while texture profile analysis index decreased between chopping 5 and 6 min. The relaxation time T21 (bound water) and its peak area ratio decreased, while the ratio of T22 peak area (immobilized water) in raw meat batters gradually increased with the extension of chopping time. However, T22 was opposite after being heated and a new component T23 (free water) appeared (T2i is the spin – spin relaxation time for the ith component.). The initial damping factor (Tan δ) gradually decreased and there were significant difference between 4 and 5 min of chopping time. There were significantly positive correlations between the ratio of peak area of T22 and chopping time, the storage modulus (G′), cooking loss, and L*, respectively. Continued chopping time could improve the peak area proportion of T22 in raw meat batters. Further, the higher the peak area proportion of T22 in raw meat batters, the cooking loss of heated meat gel was higher. Also, the stronger the mobility of immobilized water in meat batter, the higher the L* of the fresh meat batters. Thus, it is revealed that the physicochemical properties of meat batter are significantly influenced by chopping time which further affects the water holding capacity and the texture of emulsification gel. [ABSTRACT FROM AUTHOR]

New microstructures with interesting, unique and stable textures, particularly relevant to food systems were created by redispersing Microfibrillar cellulose (MFC). This paper reports the interactions between microfibrillar cellulose and carboxymethyl cellulose (CMC) in redispersed aqueous suspensions, by using rheological measurements on variable ratios of MFC/CMC and correlating these with apparent water mobility as determined by time domain NMR. MFC is a network of cellulose fibrils produced by subjecting pure cellulose pulp to high-pressure mechanical homogenisation. A charged polymer such as CMC reduces the aggregation of microfibrillar/fibre bundles upon drying. Small amplitude oscillatory rheological analysis showed viscoelastic gel-like behaviour of suspensions which was independent of the CMC content in the MFC suspension. A viscous synergistic effect was observed when CMC was added to MFC before drying, leading to improved redispersibility of the suspension. Novel measurements using NMR relaxation suggested that the aggregated microfibrillar/fibre bundles normally dominate the relaxation times (T 2 ). The dense microfibrillar network plays an important role in generating stable rheological properties and controlling the mobility of the polymer and hence the apparent mobility of the water in the suspensions. [ABSTRACT FROM AUTHOR]

This study compares by means of new and advanced destabilization protocols the efficiency of new chemistry environmentally friendly (yellow) demulsifiers with already commercially available red demulsifiers in destabilizing two types of water-in-oil (w/o) emulsions: petroleum crude oil emulsions and model dense packed layers (DPLs). Oil–water separation profiles were measured by low-field nuclear magnetic resonance (NMR), which allows monitoring the water content as well as the mean droplet size in the emulsion as function of the sample height and the time. Separation profiles measured by NMR depicted an increase of the free water release kinetics as the concentration of demulsifier as well as the sedimentation rate increased. The water resolution was not substantially improved by increasing the concentration further while the water quality was worse, most likely due to adsolubilization. There was no observation of DPL formation in these crude oil emulsions. Four different demulsifiers were tested on a model DPL and compared with normal crude oil emulsions. One chemical showed higher efficiency in destabilizing DPL than destabilizing crude oil emulsion. The interfacial rheological properties for one of the systems showed a slight increase in the elastic modulus (E′), as the concentration of demulsifier increased. The increment of the elastic modulus is not totally understood. The most central parameters were represented by principal component analysis (PCA). PCA did not contribute in a better characterization of the chemicals. The new-generation yellow demulsifiers did not reproduce the efficiency of commercially available, less environmentally friendly, (red) demulsifiers. [ABSTRACT FROM PUBLISHER]

[Display omitted] Drug-loaded emulsions for spray drying should be optimised for their rheological behaviour and stability under operating conditions, as this is essential for achieving the desired physicochemical properties of the final dry product. Our aim was therefore to investigate the structure and stability of a water-in-oil (W/O) emulsion containing vancomycin hydrochloride as the active ingredient in the aqueous phase, poly(d , l -lactide- co -glycolide) as the structural polymer in the dichloromethane-based organic phase, and various stabilisers using low-field nuclear magnetic resonance (LF NMR) and rheological characterisation. Four emulsions were tested, namely-one without stabiliser, one with Poloxamer® 407, one with chitosan and Span™ 80 and one with chitosan only. The theoretical interpretation of the rheological data allowed the determination of the velocity and the shear rate/stress profiles inside the feed path of the W/O emulsion, aspects that are critical for the industrial scale-up of the emulsion drying process. In addition, LF NMR demonstrated that shaking was sufficient to restore the original emulsion structure and that the droplet size of all emulsions was in the range of 1–10 μm, although the emulsion with chitosan had the narrowest droplet size distribution and the higher zero shear viscosity, which accounts for the increased long-term stability due to impeded droplets movement. [ABSTRACT FROM AUTHOR]

This paper is devoted to the characterization and processing of high molar mass vinyl-bearing polysiloxanes in high consistency silicone rubber (HCR) formulations. The molar masses of five different polydimethylsiloxane gums, bearing vinyl groups at the ends and along their chains, were evaluated by size exclusion chromatography and rheometry. 29Si and 1H NMR spectroscopy allowed the precise determination of the vinyl content and of the distribution in the different polymers. Typical HCRs formulated from these gums were heat-cured to process silicone rubber materials that were then tested mechanically. The macromolecular properties were correlated to the final material network structure. The amount of reactive vinyl moieties, rather than their distribution along or at the end of chains, is a key parameter to tailor the material mechanical properties. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The combination of Low-Field NMR relaxometry (LF-NMR) and rheological analyses was used to investigate the kinetics of aging and structural evolution of salt-free aqueous Laponite dispersions with concentrations ranging from 0.33 to 2.00 wt%. The examination of LF-NMR results reveals that the rate of nanoclay delamination increases with increasing Laponite concentration while its degree decreases. Furthermore, the LF-NMR results were interpreted together with rheological results to assess the kinetics of processes occurring on different length scales reflecting on the time evolution of the three-dimensional structure. The structural evolution is described by the definition and comparison of three different characteristic times. The LF-NMR decay time (t r) designates the time required for Laponite delamination. The induction time (t i) indicates when interparticle edge-face interactions become effective enough for incipient networking. The gelation time (t g) corresponds to sufficiently high degree of interparticle connectivity for the development of a macroscopic gel behavior. The comparison of t i and t g , on one hand, and t r , on the other hand, allows to conclude that for low concentration Laponite dispersions nanoclay delamination is a prerequisite for the formation of the new dispersion structure with a macroscopic gel behavior. Interestingly, the development of the new structure, based on orientation of clay disks into edge-to-face pattern and mutual interparticle attractive interactions, starts when the delamination process is still running. [ABSTRACT FROM AUTHOR]