Search for Author, Title, Keyword
Water Activity in Biological Systems – A Review
 
More details
Hide details
Publication date: 2012-03-31
 
Pol. J. Food Nutr. Sci. 2012;62(1):5–13
 
KEYWORDS
ABSTRACT
Water deserves a major attention by researchers dealing with biological systems and related materials, like food, since it is ubiquitous and can be used like a “native” probe to garner information about the hosting system, provided it may be freely displaced across. Its thermodynamic potential, namely, the water activity, aW, is related to that of the other compounds of the system considered via the Gibbs-Duhem relationship reflecting the extent of the residual availability of water to solvate further solutes and sustain the molecular mobility of the bio-polymeric compounds. As for the experimental approaches to aW, this short review re-addresses the reader to other publications, while devotes a section to the Knudsen thermo-gravimetry that was used by the authors to determine the desorption isotherms of many food systems and related aqueous compounds. The paper remarks the importance of a preliminary assessment of water mobility and recalls the concept of “critical aW “ that takes into account the reduced mobility of water molecules in the vicinity of the glass transition. This opens the question of the reliability of sorption isotherms which encompass a wide aW range and the interpretation of the observed adsorption/desorption hysteresis. The multi-phase character of many biological systems is another issue of interest related to the reliability of the experimental approaches to aW . As examples of the role of aW on the stability of bio-systems and on the practice of a technological treatment, protein unfolding and osmo-dehydration of fruit pulps are reported.
 
CITATIONS (18):
1.
Physico-chemical Aspects of Textile Coloration
 
2.
Methods for measuring water activity (aw) of foods and its applications to moisture sorption isotherm studies
Lida Zhang, Da-Wen Sun, Zhihang Zhang
Critical Reviews in Food Science and Nutrition
 
3.
Habitability of Other Planets and Satellites
Roberto Barbieri
 
4.
Knudsen thermogravimetry approach to the thermodynamics of aqueous solutions
Alberto Schiraldi, Marco Signorelli, Dimitrios Fessas
The Journal of Chemical Thermodynamics
 
5.
A microtensiometer capable of measuring water potentials below −10 MPa
Vinay Pagay, Michael Santiago, David Sessoms, Erik Huber, Olivier Vincent, Amit Pharkya, Thomas Corso, Alan Lakso, Abraham Stroock
Lab Chip
 
6.
Stool consistency is strongly associated with gut microbiota richness and composition, enterotypes and bacterial growth rates
Doris Vandeputte, Gwen Falony, Sara Vieira-Silva, Raul Tito, Marie Joossens, Jeroen Raes
Gut
 
7.
Encyclopedia of Food Microbiology
K. Prabhakar, E.N. Mallika
 
8.
Cell wall composition strongly influences mesophyll conductance in gymnosperms
Marc Carriquí, Miquel Nadal, María Clemente‐Moreno, Jorge Gago, Eva Miedes, Jaume Flexas
The Plant Journal
 
9.
Metrological challenges for measurements of key climatological observables. Part 4: atmospheric relative humidity
J Lovell-Smith, R Feistel, A Harvey, O Hellmuth, S Bell, M Heinonen, J Cooper
Metrologia
 
10.
The photosynthesis game is in the "inter-play": Mechanisms underlying CO2 diffusion in leaves
J. Gago, D.M. Daloso, M. Carriquí, M. Nadal, M. Morales, W.L. Araújo, A. Nunes-Nesi, A.V. Perera-Castro, M.J. Clemente-Moreno, J. Flexas
Environmental and Experimental Botany
 
11.
Changes in Mouse Gut Microbial Community in Response to the Different Types of Commonly Consumed Meat
Zhimin Zhang, Dapeng Li, Rong Tang
Microorganisms
 
12.
Inactivation kinetics of Geobacillus stearothermophilus spores by a peracetic acid or hydrogen peroxide fog in comparison to the liquid form
Hasmik Hayrapetyan, Louise Nederhoff, Martijntje Vollebregt, Hennie Mastwijk, Groot Nierop
International Journal of Food Microbiology
 
13.
Principles of Food Chemistry
Yrjo Roos, John Finley, John deMan
 
14.
Carbon and Nitrogen Cycling in Soil
Julio Filho, Gildemberg Junior
 
15.
Encapsulation of volatiles in nanofibrous polysaccharide membranes for humidity-triggered release
Erika Mascheroni, Carlos Fuenmayor, Maria Cosio, Silvestro Di, Luciano Piergiovanni, Saverio Mannino, Alberto Schiraldi
Carbohydrate Polymers
 
16.
Calorimetry and thermal analysis in food science
Alberto Schiraldi, Dimitrios Fessas
Journal of Thermal Analysis and Calorimetry
 
17.
Development and evaluation of antibacterial electrospun pea protein isolate-polyvinyl alcohol nanocomposite mats incorporated with cinnamaldehyde
Neda Maftoonazad, Maryam Shahamirian, Dalia John, Hosahalli Ramaswamy
Materials Science and Engineering: C
 
18.
Cell wall composition and thickness affect mesophyll conductance to CO2 diffusion in Helianthus annuus under water deprivation
Margalida Roig-Oliver, Panagiota Bresta, Miquel Nadal, Georgios Liakopoulos, Dimosthenis Nikolopoulos, George Karabourniotis, Josefina Bota, Jaume Flexas, Andrea Braeutigam
Journal of Experimental Botany
 
eISSN:2083-6007
ISSN:1230-0322