scholarly journals The influence of wheat bran and pectin on the distribution of water in rat caecal contents and faeces

1993 ◽  
Vol 69 (3) ◽  
pp. 913-920 ◽  
Author(s):  
Elizabeth F. Armstrong ◽  
Martin A. Eastwood ◽  
W. Gordon Brydon

Wheat bran and pectin (100 g/kg) were added to a basal diet and fed to rats. An in vitro dialysis technique was used to measure the distribution of caecal and faecal water between the bound, i.e. that held by bacteria and undigested macromolecules, and free water. Bran increased wet (67%) and dry (74%) faecal weight. Pectin increased wet faecal weight (59 %), but did not influence dry weight. In faeces both bran and pectin increased the amount of total and bound water, but only pectin increased total and bound water when expressed on a dry weight basis. Caecal wet (90%) and dry (67%) weights increased with pectin but not with bran. Bran did not change total water but increased bound water whereas pectin increased both. This suggests that water contributed more to the increase in stool bulk in the pectin- supplemented animals due to free and bound water associated with both increased numbers of bacteria and residual pectin. Pectin altered the distribution of water in faeces. Bran has no effect on water distribution and is only partly fermented. The residual water-holding capacity leads to an increased wet and dry stool output.

Solid Earth ◽  
2014 ◽  
Vol 5 (1) ◽  
pp. 537-555 ◽  
Author(s):  
M. E. T. Quinquis ◽  
S. J. H. Buiter

Abstract. Subduction of oceanic lithosphere brings water into the Earth's upper mantle. Previous numerical studies have shown how slab dehydration and mantle hydration can impact the dynamics of a subduction system by allowing a more vigorous mantle flow and promoting localisation of deformation in the lithosphere and mantle. The depths at which dehydration reactions occur in the hydrated portions of the slab are well constrained in these models by thermodynamic calculations. However, computational models use different numerical schemes to simulate the migration of free water. We aim to show the influence of the numerical scheme of free water migration on the dynamics of the upper mantle and more specifically the mantle wedge. We investigate the following three simple migration schemes with a finite-element model: (1) element-wise vertical migration of free water, occurring independent of the flow of the solid phase; (2) an imposed vertical free water velocity; and (3) a Darcy velocity, where the free water velocity is a function of the pressure gradient caused by the difference in density between water and the surrounding rocks. In addition, the flow of the solid material field also moves the free water in the imposed vertical velocity and Darcy schemes. We first test the influence of the water migration scheme using a simple model that simulates the sinking of a cold, hydrated cylinder into a dry, warm mantle. We find that the free water migration scheme has only a limited impact on the water distribution after 1 Myr in these models. We next investigate slab dehydration and mantle hydration with a thermomechanical subduction model that includes brittle behaviour and viscous water-dependent creep flow laws. Our models demonstrate that the bound water distribution is not greatly influenced by the water migration scheme whereas the free water distribution is. We find that a bound water-dependent creep flow law results in a broader area of hydration in the mantle wedge, which feeds back to the dynamics of the system by the associated weakening. This finding underlines the importance of using dynamic time evolution models to investigate the effects of (de)hydration. We also show that hydrated material can be transported down to the base of the upper mantle at 670 km. Although (de)hydration processes influence subduction dynamics, we find that the exact numerical implementation of free water migration is not important in the basic schemes we investigated. A simple implementation of water migration could be sufficient for a first-order impression of the effects of water for studies that focus on large-scale features of subduction dynamics.


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 612
Author(s):  
Shimaa Abdelazeem ◽  
Ken-ichi Takeda ◽  
Kazuhiro Kurosu ◽  
Yutaka Uyeno

Persimmon skin (PS), while representing an attractive feed source, requires an appropriate preservation procedure to increase its shelf life. We assessed the fermentation quality, in vitro ruminal incubation, and intake of persimmon skin silage ensiled with different dry absorbents. We prepared the silage on a table scale (Experiment 1) and evaluated five different mixtures: PS without an additive, PS plus Lactobacillus buchneri inoculum (LB), and PS plus LB plus each of the absorbents kraft pulp, wheat bran, or beet pulp. We opened the laboratory bags, kept at 25 °C, at 0, 14, 28, and 60 days for fermentation quality and chemical analysis (n = 3 for each measurement). Further, with an in vitro rumen simulated cultivation study (Experiment 2), we evaluated the fermentation pattern of PS with a mixture of two absorbents (kraft pulp and wheat bran) either raw (no fermentation) or ensiled (n = 4 for each treatment). Finally, we conducted an in vivo experiment using six dry ewes assigned based on their body weight to two experimental groups in a crossover design of two periods (Experiment 3). We fed a control group a 100% basal diet (tall fescue hay and concentrate mixture) and ensiled PS (PSS) group, a 20% dry matter substitution of tall fescue with PS silage mixed with kraft pulp as the sole absorbent. The results of Experiment 1 show, regardless of the absorbents used, the effluent volume of the lab bags was lower in absorbent-treated groups (p < 0.001). In Experiment 2, the condition of the PS with absorbents (raw or ensiled) did not affect the total gas production (p > 0.05), but we observed an increased propionate proportion in PSS with absorbents compared to basal diet (p = 0.019). The proportion of methane to the total gas in PSS group was considerably reduced compared with that in the other groups (p < 0.001). As we did this incubation study with a single run, a more detailed evaluation in the future would verify these observations. In the animal trial (Experiment 3), dry matter intake was similar between groups (p > 0.05), but ewes spent a shorter time eating in the PSS-fed group (p = 0.011). Here we present the practical use of PSS as part of ruminant feed in which dry absorbents prevented dry matter loss.


1992 ◽  
Vol 68 (2) ◽  
pp. 473-482 ◽  
Author(s):  
Christine A. Edwards ◽  
Jacqueline Bowen ◽  
W. Gordon Brydon ◽  
Martin A. Eastwood

The colonic fermentation of ispaghula, a mucilage fromPlantago ovatacomposed mainly of arabinoxylans, and its effects on stool output and caecal metabolism were investigated. Four groups of eight rats were fed on a basal diet (45 g non-starch polysaccharides/kg) for 28 d. The diet was then supplemented with ispaghula (g/kg; 0, 5, 15 or 50) for 28 d. Ispaghula increased stool dry weight and apparent wet weight but faecal water-holding capacity (amount of water held per g dry faecal material at 0.2 mPa) was unchanged. The extent of faecal drying in the metabolism cages was measured for rats fed on the basal diet and 50 g ispaghula/kg diet. At the faecal output levels encountered, only an 8% loss of wet weight would be predicted over 24 h and this was independent of diet. Faecal short-chain fatty acid (SCFA) concentration did not change but SCFA output increased. The molar proportion of SCFA as propionic acid increased and faecal pH was reduced. Values from pooled faecal samples suggested that approximately 50% of the ingested ispaghula was excreted by the 50 g ispaghula/kg diet group. Diaminopimelic acid (a constituent of bacterial cells) concentrations fell but output was unchanged indicating no change in bacterial mass. Similar changes were seen in the caecal contents but caecal pH and SCFA were unaffected. Ispaghula increased both caecal and colonic tissue wet weight and colonic length. Our results suggest that ispaghula is partly fermented in the rat caecum and colon, and loses its water-holding capacity. However, it is still an effective stool bulker and acts mainly by increasing faecal water by some unknown mechanism


2008 ◽  
Vol 22 (5) ◽  
pp. 405-417 ◽  
Author(s):  
Tanja M. Greve ◽  
Kristine B. Andersen ◽  
Ole F. Nielsen

The penetration mechanism of dimethyl sulfoxide (DMSO) in human skinin vivoandin vitroand pig ear skin in vitro was studied using attenuated total reflectance (ATR) Fourier transform (FT) infrared (IR) and near-FT-Raman spectroscopy. The results showed changes in the conformation of the skin keratins from an α-helical to a β-sheet conformation. These changes were proved to depend on the concentration of free water in the sample as DMSO tended to bind to free water before the protein-bound water was replaced and the protein conformational changes were induced. The induced conformational changes were shown to be completely reversible as the proteins are returned to their original state within 20 h after the treatment with DMSO. The penetration depth of DMSO was shown to depend on the time of exposure – however, after only 15 min DMSO has penetrated thestratum corneum, which is the skin barrier.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3395
Author(s):  
Feiyan Mao ◽  
Yingjie Zhao ◽  
Yiping Zhang ◽  
Zhou Chen ◽  
Lu Yin

The dewatering of dredged sludge is a critical step in the minimization and reutilization of this solid waste. However, there is a lack of available literature on the fundamental drying characteristics of dredged sludge. In this work, two kinds of typical sludge dredged from an urban watercourse were tested by low-field NMR to investigate the water distribution in sludge and it was found that water contained in sludge can be classified into three categories: free water, capillary water and bound water. In addition, a novel model was proposed based on the Lennard-Jones equation and Kelvin law to quantitatively evaluate the binding energy during drying. Further, the model results were experimentally verified by thermogravimetry differential thermal analysis (TG-DTA). Results show that the trends of the model are consistent with the experimental values and the gradient of energy consumption during dehydration can be divided into three main stages. In stage 1, the total energy required for dewatering equals the latent heat of free water. In stage 2, binding energy reaches dozens to hundreds of kJ/kg accounting for capillary action. In stage 3, binding energy increases steeply reaching almost thousands of kJ/kg due to intermolecular interactions. All the discovered aspects could improve the management and disposal of dredged sludge from an energy cost perspective.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1139 ◽  
Author(s):  
Lihong Pan ◽  
Jiali Xing ◽  
Xiaohu Luo ◽  
Yanan Li ◽  
Dongling Sun ◽  
...  

Moisture content is an important factor that affects rice storage. Rice with high moisture (HM) content has superior taste but is difficult to store. In this study, low-dose electron beam irradiation (EBI) was used to study water distribution in newly harvested HM (15.03%) rice and dried rice (11.97%) via low-field nuclear magnetic resonance (LF-NMR). The gelatinization, texture and rheological properties of rice and the thermal and digestion properties of rice starch were determined. Results showed that low-dose EBI could change water distribution in rice mainly by affecting free water under low-moisture (LM) conditions and free water and bound water under HM conditions. HM rice showed smooth changes in gelatinization and rheological properties and softened textural properties. The swelling power and solubility index indicated that irradiation promoted the depolymerization of starch chains. Overall, low-dose EBI had little effect on the properties of rice. HM rice showed superior quality and taste, whereas LM rice exhibited superior nutritional quality. This work attempted to optimize the outcome of the EBI treatment of rice for storage purposes by analyzing its effects. It demonstrated that low-dose EBI was more effective and environmentally friendly than other techniques.


2001 ◽  
Vol 44 (10) ◽  
pp. 177-183 ◽  
Author(s):  
J. Kopp ◽  
N. Dichtl

Dewaterabilty of sewage depends on the physical water distribution. The various types of water in sewage sludge are mainly distinguished by type and intensity of their physical bonding to the solids. In a sewage sludge suspension different types of water can be distinguished. These are free water, which is not bound to the particles, interstitial water, which is bound by capillary forces between the sludge flocs, surface water, which is bound by adhesive forces and intracellular water. Only free water can be separated during mechanical dewatering. It can be shown, that thermo-gravimteric measurement of the free water content leads to an exact prediction of full-scale dewatering results. Maximum dewatering results are reached by separating all free water during centrifugation. Furthermore on the basis of the drying curve an estimation of water binding energies can be achieved. The binding energy for free water is less than 0,28 kJ/kg water. The binding energy for bound water (sum of surface and intracellular water) is higher than 5 kJ/kg water.


Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2499
Author(s):  
Xiao Sun ◽  
Jinjie You ◽  
Yan Dong ◽  
Ligen Xu ◽  
Clay J. Maynard ◽  
...  

The scope of this paper was to investigate the effects of water distribution differences on the quality and feasibility of chicken patties supplemented with woody breast (WB). Chicken patties, containing differing amounts of WB (0%, 25%, 50%, 75%, 100%) were analyzed using low-field NMR. Quality differences between chicken patties were further evaluated by combining lipid and protein properties, fry loss (FL), color (L*, a*, b*), texture (hardness, springiness, chewiness, cohesiveness, resilience), microstructure, and sensory characteristics. The results expressed that both lipid and protein oxidation increased and immobilized water in chicken patties can be converted to free water more easily with increasing levels of WB. Additionally, the free water ratio decreased, water freedom increased, and the bound water ratio increased (p < 0.05). Fry loss, color, texture (hardness, springiness, chewiness), microstructure, and sensory (character, organization, taste) characteristics deteriorated significantly when the WB inclusion level exceeded 25%. Particularly, characteristics of texture (chewiness and character) and sensory (character and organization) decreased significantly as WB inclusion increased past 25% (p < 0.01). Furthermore, fry loss, texture, and overall microstructure partially confirmed the moisture variation of chicken patties as the potential cause of the abnormal quality. Although the experimental data expressed that mixing to 35% WB inclusion was feasible, the practical and economic impact recommends inclusion levels to not exceed 30%.


Author(s):  
Qingwen Ni ◽  
Huijie Leng ◽  
Daniel P. Nicolella

Bone quality in terms of water distribution, porosity, and pore size distributions in cortical bone and relate these measures can be used to correlate bone mechanical properties. The objective of this paper is to demonstrate that non-destructive low-field NMR technique can be used to determine the mobile and the bound water distribution, and further determine the loosely and the tightly bound water in cortical bone in vitro.


Author(s):  
Qingwen Ni ◽  
Naniel P. Nicolella

Previous studies have shown that the age-related increase in bone porosity results a decrease in bone strength, and porosity is related to the volume of mobile water in the pores. In addition, since water is also bound to collagen and mineral, changes in the amount of bound water will potentially affect the bone strength. It is known that the removal of the loosely bound water (via hydrogen bonding) requires less energy than the water molecules trapped inside collagen molecules, which in turn requires similar or less energy than water molecules bound to the surface charges of mineral apatite (more ionic in nature). Also, water that is imbedded in the lattice of hydroxyapatite (more covalent in nature) requires the highest energy to dislodge. However, there is no traditional method that can determine mobile and bound water, further for loosely and tightly bound ware accurately, non-destructively and non-invasively. Here, we propose that by using NMR Car-Purcell-Meiboom-Gill (CPMG) spin-spin relaxation measurement to determine the mobile water, and the NMR inversion T2-FID spectrum derived from NMR free induction decay (FID) measurements for estimating the bound and free water distribution. Furthermore, after comparison of the total water lost (weighing method) within tissue by using drying (free dry) on the air to the total mobile water lost measured by NMR CPMG method, then, the total loosely bound water lost can be estimated. Following this, the mechanical test will be used to evaluate the bone quality related to the tightly and loosely bound water within bone. This information can be used to further assessment of bone quality.


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