Properties of starch hydroxypropyl methylcellulose based films obtained by compression molding
[EN] Corn starch glycerol (1:0.3) films, containing or not citric acid (1 g/100 g starch) and HPMC (10 and 20 g/100 g starch), are obtained by compression molding. The microstructure of the films, the thermal behavior, the X-ray diffraction spectra and the physical properties (mechanical, barrier an...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2014 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/75089 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/75089 |
| Access Level: | acceso abierto |
| Palabra clave: | Starch Compression molding Citric acid HPMC Crystallization TECNOLOGIA DE ALIMENTOS |
| Sumario: | [EN] Corn starch glycerol (1:0.3) films, containing or not citric acid (1 g/100 g starch) and HPMC (10 and 20 g/100 g starch), are obtained by compression molding. The microstructure of the films, the thermal behavior, the X-ray diffraction spectra and the physical properties (mechanical, barrier and optical) were analyzed after 1 and 5 storage weeks at 25 °C and 53% relative humidity. The bonded citric acid and film solubility were also determined. Starch HPMC blend films showed a dispersed phase of HPMC in a continuous, starch-rich phase with lower glass transition than HPMC-free films. The addition of citric acid also provoked a decrease in glass transition in line with the partial hydrolysis of starch chains. Both components implied a decrease in the water vapour permeability while the oxygen permeability slightly increased. Although citric acid only provoked a small hardening effect in the films, it greatly decreased their extensibility (weak cross-linking effect), which seems to increase during film storage. Starch crystallization during storage was inhibited by both citric acid and HPMC. |
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