A Preliminary Study on Antimicrobial Edible Films from Pectin and Other Food Hydrocolloids by Extrusion Method

ABSTRACT

Antimicrobial edible films were prepared from natural fiber of pectin and other food hydrocolloids for food packaging or wrapping by extrusion followed by compression or blown film method. Microscopic analysis revealed a well-mixed integrated structure of extruded pellets and an even distribution of the synthetic hydrocolloid in the biopolymers. The resultant composite films possess mechanical properties that are comparable to films cast from most natural hydrocolloids that are consumed as foods or components in processed foods. The inclusion of poly(ethylene oxide) alters the textures of the resultant composite films and therefore demonstrates a new technique for the modification of film properties. The composite films were produced in mild processing conditions, thus the films are able to protect the bioactivity of the incorporated nisin, as shown by the inhibition of Listeria monocytogenes bacterial growth by a liquid incubation method.

KEYWORDS:

• Pectin
• antimicrobial
• fiber
• films
• extrusion

Authors acknowledge Dr. Peter H. Cooke, Mr. Nicholas Latona, Ms. Guo-ping Bao, Dr. David R. Coffin, and Dr. Vitoria L. Finkensdadt for their technical assistance.