الفهرس 
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Abstract
Interest in biodegradable materials for packaging and agricultural uses has
grown in recent years. Plant proteins have been proposed as inexpensive,
renewable, and abundant feedstock. Zein was investigated based on value-added
considerations and on the unique thermoplastic and hydrophobic properties of it.
Films prepared from zein are known to be hard and brittle, thus requiring the
addition of plasticizers to improve flexibility. Cross-linked and chemical modified
zein films as an alternative to packaging films consisting of non-degradable
polymers were prepared to evaluate mechanical, thermal, contact angle, surface
morphology and color properties of the resulting film, as affected by formulation
process (cross-linker type, cross-linker concentration and type of aldehydes used in
chemical modification). Zein films were obtained through a simple solvent casting
method. Zein with concentration 8% was dissolved in 88 % aqueous ethanol
solution at room temperature for cross-linking process. In chemical modification
process, 10% zein was used at different times and temperatures.
The resulting zein films showed good appearance and flexibility. The prepared
films showed improvement in mechanical properties when using eugenol & citric
acid and eugenol & succinic acid as a cross-linker. On the other hand in case of
chemical modification the prepared films showed very good improvement in
elongation properties for the films. The prepared films showed antimicrobial effect
towards pathogenic strains (seven strains) depending on type of cross-linkers
compound used or type of aldehyde used in chemical modification. Finally addition
of bacteriocin like nisin improves antimicrobial effect of films towards specific
strains.