Effects of Different Moisture Contents on Physical Properties of PVA-Gelatin Films

Autor(es)

Bergo, P. ^[1] ; Moraes, I. C. F. ^[1] ; Sobral, P. J. A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, FZEA, Food Engn Dept ZAZ, BR-13630900 Pirassununga - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FOOD BIOPHYSICS; v. 7, n. 4, p. 354-361, DEC 2012.
• Citações Web of Science: 9

Resumo

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 A degrees 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. (AU)

• Processo FAPESP: 05/54688-7 - Estudo das interações entre polióis e biopolímeros em filmes comestíveis por espectroscopia de microondas e de infravermelho
• Beneficiário: Paulo Victor Albuquerque Bergo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado