Abstract
In this work, it was investigated the effect of different moisture contents on PVA-gelatin films by means of dielectric properties, infrared spectroscopy, microwave response and gravimetric method. The films were elaborated from a blend of gelatin and PVA, with 0 and 25 % glycerol. The sorption isotherms were determined by gravimetric methods, at 25 °C. A capacimeter was used for dielectric measurements, and a device called SOLFAN setup was used for microwave measurements. The sorption isotherms were markedly affected by the glycerol content and relative humidity, due to the hygroscopic nature of the films. The dielectric constant and the microwave response signal were also strongly affected by the moisture and glycerol content in the films. Finally, Infrared spectra showed some changes in the amide peak positions, attributed to the modifications in the interactions between the macromolecules. The behaviors obtained in this work were explained on the basis the way the water enters in the film matrix.
Similar content being viewed by others
References
N. Gontard, S. Guilbert, Bio-packaging: technology and properties of edible and/or biodegradable material of agricultural origin. Boletim da SBCTA 30(1), 3–15 (1996)
P.J.A. Sobral, F.C. Menegalli, M.D. Hubinguer, M.A. Roques, Mechanical, water vapor barrier and thermal properties of gelatin based edible films. Food Hydrocolloids 15(4–6), 423–432 (2001)
S. Rawdkuen, S. Sai-Ut, S. Benjakul, Properties of gelatin films from giant catfish skin and bovine bone: a comparative study. Eur. Food Res. Technol. 231(6), 907–916 (2010)
J.G. Estaca, A.L. Lacey, M.E.L. Caballero, M.C.G. Guillen, P. Montero, Biodegradable gelatin–chitosan films incorporated with essential oils as antimicrobial agents for fish preservation. Food Microbiol. 27(7), 889–896 (2010)
P. Bergo, W.M. Pontuschka, J.M. Prison, Dielectric properties and physical features of phosphate glasses containing iron oxide. Mater. Chem. Phys. 108(1), 142–146 (2008)
M. Roussenova, J.P. Enrione, D. Calderon, A.J. Taylor, J. Ubbink, M.A. Alam, A nanostructural investigation of glassy gelatin oligomers: molecular organization and interactions with low molecular weight diluents. New J. Phys. 14, 1–18 (2012)
I.C. Moraes, G.G.D. Silva, R.A. Carvalho, A.M.Q.B. Habitante, P. Bergo, P.J.A. Sobral, Influence of the degree of hydrolysis of poly(vinyl alcohol) on the physical properties of films based on blends of gelatin and poly(vinyl alcohol) plasticized with glycerol. Cienc. Tecnol. Aliment. 28(3), 738–745 (2008)
P. Bergo, P.J.A. Sobral, Effects of plasticizer on physical properties of pigskin gelatin films. Food Hydrocolloids 21, 1285–1289 (2007)
P. Bergo, P.J.A. Sobral, Microwave transmittance in gelatin-based films. Meas. Sci. Technol. 17, 1–4 (2006)
S. Iwamoto, H. Kumagai, Y. Hayashi, O. Miyawaki, Conductance and relaxations of gelatin films in glassy and rubbery states. Int. J. Biol. Macromol. 26(5), 345–351 (1999)
S. Sudo, Dielectric properties of the free water in hydroxypropyl cellulose. J. Phys. Chem. B 115(1), 2–6 (2011)
S. Clerjon, J.D. Daudin, L.L. Damez, Water activity and dielectric properties of gels in the frequency range 200 MHz-6GHz. Food Chem. 82(1), 87–97 (2003)
Y. Hayashi, N. Shinyashiki, S. Yagihara, Dynamical structure of water around biopolymers investigated by microwave dielectric measurements using time domain reflectometer method. J. Non-Cryst. Solids 305(1–3), 328–332 (2002)
M.S. Venkatesh, G.S.V. Raghavan, An overview of microwave processing and dielectric properties of agri-foods materials. Biosyst. Eng. 88(1), 1–18 (2004)
I. Yakimets, N. Wellner, A.C. Smith, R.H. Wilson, I. Farhat, J. Mitchell, Mechanical properties with respect to water content of gelatin films in glassy state. Polymer 46, 12577–12585 (2005)
V.E. Khutorsky, S.B. Lang, Very strong influence of moisture on pyroelectric and dielectric properties of triglycine sulfate-gelatin films. J. Appl. Phys. 82(3), 1288–1292 (1997)
R.A. Carvalho, C.R.F. Grosso, P.J.A. Sobral, Effects of chemical treatment on the mechanical properties, water vapour permeability and sorption isotherms of gelatin-based films. Packag. Technol. Sci. 21, 165–169 (2008)
T.M.C. Maria, R.A. Carvalho, P.J.A. Sobral, A.M.B.Q. Habitante, J.S. Feria, The effect of the degree of hydrolysis of the PVA and the plasticizer concentration on the color, opacity, and thermal and mechanical properties of films based on PVA and gelatin blends. J. Food Eng. 87(2), 191–199 (2008)
H. Mansur, A.N. Sadahira, A.N. Souza, A.P.A. Mansur, FTIR spectroscopy characterizations of poly (vinyl alcohol) hydrogel with different hydrolysis degree and chemically crosslinked with glutaraldehyde. Mater. Sci. Eng. C 28, 539–548 (2008)
D.A. Prystupa, A.M. Donald, Infrared study of gelatin conformations in the gel and sol states. Polimers Gels Netw. 4, 87–110 (1996)
V. Renugopalakrishnan, G. Chandrakasan, S. Moore, T.B. Hutson, C.V. Berney, R.S. Bhatvagar, Bound water in collagen. Evidence from Fourier transform infrared and Fourier transform infrared Photoacoustic spectroscopic study. Macromolecules 22, 4121–4124 (1989)
A. Sionkowska, M. Wisniewski, J. Skopinska, C.J. Kennedy, T.J. Wess, Molecular interactions in collagen and chitosan blends. Biomaterials 25, 795–801 (2004)
Acknowledgments
To FAPESP for the fellowship of Bergo, P. (05/54688-7).
Declaration of Conflict Interest
The authors declare that they have no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Bergo, P., Moraes, I.C.F. & Sobral, P.J.A. Effects of Different Moisture Contents on Physical Properties of PVA-Gelatin Films. Food Biophysics 7, 354–361 (2012). https://doi.org/10.1007/s11483-012-9273-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11483-012-9273-0