scholarly journals A multiscale approach to estimate the cellular diffusivity during food drying

2021 ◽  
Author(s):  
Zachary G Welsh

Theoretical models for food drying commonly utilize an effective diffusivity solved through curve fitting based on experimental data. This creates models with limited predictive capabilities. Multiscale modeling is one approach which can help transition to a more physics-based model minimizing the empirical information required while improving a model’s predictive capabilities. However, to enable an accurate scaling operation, multiscale models require diffusivity at a fine scale (microscale). Measuring these properties is experimentally costly and time consuming as they are often temperature and/or moisture dependent. This research conducts an inverse analysis on a multiscale homogenization food drying model to deduce the temporal diffusivity of intracellular water. A representation of the real cellular water breakdown was considered and appropriate assumptions to represent its cellular heterogeneity, in relation to time, were investigated. The work uncovered that a linear decrease in intracellular water content could be assumed and thus a function for its diffusivity was developed. The proposed function is in terms of sample temperature and intracellular water content opening the possibilities to be applied to various food materials.

1976 ◽  
Vol 231 (5) ◽  
pp. 1568-1572 ◽  
Author(s):  
M DiGirolamo ◽  
JL Owens

Epididymal adipose tissue composition and adipocyte water content were studied in male rats during growth and development of spontaneous obesity. The data show that a highly significant positive correlation exists between fat-cell volume and intracellular water space (IWS) (r=.967, P less than .001). Intracellular water, expressed as picoliters per fat cell, varied from 1.5-2 in small fat cells (mean vol, 30-50 pl) to 9-10 in large cells (800-1,000 pl). When expressed as percent of fat-cell volume, IWS varied from 5-7% in the small fat cells to 1-1.3% in the large ones. Total adipose tissue water continued to increase with increasing adipose mass. Similarly, total adipocyte water increased with enlarging cell size and tissue mass. The contribution of total adipocyte water (as contrasted to that of nonadipocyte water) to total tissue water, however, was found to be limited (less than 23%) and to decline progressively with adipose mass expansion.


1977 ◽  
Author(s):  
J.S. Wiley ◽  
G. Wray ◽  
I.A. Cooper

One approach to platelet sizing is to measure the intracellular water space of platelets with 3H-H2O since the % water content of platelets remains constant in states with different platelet sizes. Fresh citrated blood was centrifuged for 10 min at 150 'g' to obtain PRP. Aliquots of PRP were briefly incubated with either 3H-H2O or 14C-sucrose then layered over 0.3 ml dibutylphthalate and spun 4 min at 8000 'g'. The cell pellet was solubilized and counted to enable spaces to be calculated. The extracellular (sucrose) space was subtracted from the total water space of the pellet to give a mean intracellular water space of 0.56 ± 0.12 μ1/108 platelets (n =19). Assuming a water content of 7 5% and a density of 1.04, the mean platelet volume for normal subjects is 7.2 fl. Gel-filtration of platelets (GFP) on Sepharose-2B reduced their mean water space by 0.12 μl/108 platelets. However the amount of shrinkage on gel-filtration depended on the initial water space of the platelets in PRP and there was a linear relation between these two variables (r = 0.82). Shrinkage was 40% for an initial platelet water space of 0.70 μl/108 platelets but there was almost no shrinkage below a water space of 0.40 μl/108 platelets. Recovery of platelets from each column averaged 8 0% and showed no relation to the reduction in the mean cell water space. The lower water space of GFP may indicate a reduction in mean cell volume due to gel-filtration.


2014 ◽  
Vol 664 ◽  
pp. 433-436
Author(s):  
Jiang Chang ◽  
Feng Xu ◽  
Guang Hua Wu ◽  
Xiao Feng Fu ◽  
Guang Li ◽  
...  

The drying rate is difficult to control for perilla leaf during the microwave vacuum drying process. Through scientific approaches, this paper made a research on the relationships between drying factors and drying rate, and established a kinetics model on microwave vacuum drying of perilla leaf. The model can predict the water content variations of perilla leaf during microwave vacuum drying, and provides a theory basis for packaging, storage and transportation for perilla leaf production.


2020 ◽  
Vol 9 (5) ◽  
pp. 1580
Author(s):  
Mateu Serra-Prat ◽  
Isabel Lorenzo ◽  
Mònica Papiol ◽  
Elisabet Palomera ◽  
Maria Bartolomé ◽  
...  

Background: In aged populations, muscle strength depends more on muscle quality than on muscle quantity, while all three are criteria for the diagnosis of sarcopenia. Intracellular water content (ICW) in lean mass (LM) has been proposed as an indicator of muscle quality related to muscle strength in older people. Objectives: To evaluate the relationship between the ICW/LM ratio, muscle strength and indicators of functional performance in obese older adults, and to assess the value of the ICW/LM ratio as an indicator of muscle quality. Methodology: Design: cross-sectional study. Population: persons aged 65–75 years with a body mass index of 30–39 kg/m2. ICW and LM were estimated by bioelectrical impedance. Hand grip, gait speed, unipedal stance test, timed up-and-go (TUG) test, Barthel score and frailty (Fried criteria) were assessed. Sarcopenia was established according to EWGSOP2 criteria. Results: Recruited were 305 subjects (66% women), mean age 68 years. The ICW/LM ratio correlated with the TUG test, gait speed and grip strength, and was also associated with sex, the unipedal stance test and frailty. Independently of age, sex and muscle mass, the ICW/LM ratio was related with gait speed, the TUG test and unipedal stance capacity. One person (0.3%) had sarcopenia defined as low muscle strength and low muscle mass, while 25 people (8.2%) had sarcopenia defined as low muscle strength and poor muscle quality (ICW/LM). With this last definition, sarcopenia was related to frailty, gait speed and the TUG test. Conclusions: ICW content in LM could be a useful muscle quality indicator for defining sarcopenia. However, more studies are required to confirm our findings for other populations.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Nobuo Geshi ◽  
Tadashi Yamasaki ◽  
Isoji Miyagi ◽  
Chris E. Conway

AbstractDecompression of a magma chamber is a fundamental condition of caldera collapse. Although theoretical models have predicted the decompression of magma chambers before caldera collapse, few previous studies have demonstrated the amount of magma chamber decompression. Here, we determine water content in quartz glass embayments and inclusions from pyroclastic deposits of a caldera-forming eruption at Aira volcano approximately 30,000 years ago and apply this data to calculate decompression inside the magma chamber. We identify a pressure drop from 140–260 MPa to 20–90 MPa during the extraction of around 50 km3 of magma prior to the caldera collapse. The magma extraction may have caused down-sag subsidence at the caldera center before the onset of catastrophic caldera collapse. We propose that this deformation resulted in the fracturing and collapse of the roof rock into the magma chamber, leading to the eruption of massive ignimbrite.


1979 ◽  
Vol 13 (2) ◽  
pp. 171-174 ◽  
Author(s):  
K. F. Rothe

Summary At different extracellular pH values fractional extra-cellular space (calculated from the distribution of 3H inulin) and fractional water content showed no significant differences. 72 h after nephrectomy both variables increased significantly. An exception to this was brain, where fractional extracellular space decreased and total intracellular water increased as a sign of brain oedema.


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