Development of films based on blends of gelatin and poly(vinyl alcohol) cross linked with glutaraldehyde


Autoria(s): ALVES, Priscila M. A.; CARVALHO, Rosemary A.; MORAES, Izabel C. F.; LUCIANO, Carla G.; BITTANTE, Ana Monica Q. B.; SOBRAL, Paulo J. A.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

19/10/2012

19/10/2012

2011

Resumo

Both gelatin and poly(vinyl alcohol) (PVA) can be cross linked with glutaraldehyde (GLU). In the case of gelatin, the GLU reacts with each e-NH2 functional group of adjacent lysine residues, while for PVA, the GLU reacts with two adjacent hydroxyl groups, forming acetal bridges. Thus it can be considered possible to cross link adjacent macromolecules of gelatin and PVA using GLU. In this context, the aims of this work were the development of biodegradable films based on blends of gelatin and poly(vinyl alcohol) cross linked with GLU, and the characterization of some of their main physical and functional properties. All the films were produced from film-forming solutions (FFS) containing 2 g macromolecules (PVA + gelatin)/100 g FFS, 25 g glycerol/100 g macromolecules, and 4 g GLU (25% solution)/100 g FFS. The FFS were prepared with two concentrations of PVA (20 or 50 g PVA/100 g macromolecules) and two reaction temperatures: 90 or 55 degrees C, applied for 30 min. The films were obtained after drying (30 degrees C/24 h) and conditioning at 25 degrees C and 58% of relative humidity for 7 days, and were then characterized. The results for the color parameters, mechanical properties, phase transitions and infrared spectra showed that some chemical modifications occurred, principally for the gelatin. However, in general, all the characteristics of the films were either typical of films based on blends of these macromolecules without cross linking, or slightly higher. A greater improvement in the properties of this material was probably not observed due to the crystallinity of the PVA, which has a melting point above 90 degrees C. The presence of microcrystals in the polymer chain probably reduced macromolecular mobility, hindering the reaction. Thus more research is necessary to produce biodegradable films with improved properties. (C) 2011 Elsevier Ltd. All rights reserved.

FAPESP[05/57781-8]

FAPESP[08/53263-0]

CNPq

Identificador

FOOD HYDROCOLLOIDS, v.25, n.7, p.1751-1757, 2011

0268-005X

http://producao.usp.br/handle/BDPI/26827

10.1016/j.foodhyd.2011.03.018

http://dx.doi.org/10.1016/j.foodhyd.2011.03.018

Idioma(s)

eng

Publicador

ELSEVIER SCI LTD

Relação

Food Hydrocolloids

Direitos

restrictedAccess

Copyright ELSEVIER SCI LTD

Palavras-Chave #Biodegradable films #Biopolymer #Protein #Chemical modification #Physical properties #MECHANICAL-PROPERTIES #THERMAL-PROPERTIES #BIODEGRADABLE FILMS #PHYSICAL-PROPERTIES #COMPOSITE FILMS #WATER-CONTENT #EDIBLE FILMS #PVA #HYDROLYSIS #PROTEINS #Chemistry, Applied #Food Science & Technology
Tipo

article

original article

publishedVersion