1. Introduction
Chitosan (poly-b-(1e4)-D-glucosamine), which is mainly made
from crustacean shells, is harmless to humans, pets, wildlife, and
the environment. It has been reported to have a number of functional
properties that make chitosan useful in nutrition; these
include its antimicrobial activity, its binding action and antioxidant
activity. Due to its biological characteristics, many applications have
been found in the food, pharmaceutical, textile, agriculture, water
treatment and cosmetic industries (Domard, 2011; Kim & Thomas,
2007; Kong, Chen, Xing, & Park, 2010; Lopez-Caballero, Gomez-
Guillen, Perez-Mateos, & Montero, 2005).
Antimicrobial activity of chitosan has been demonstrated
against many bacteria, fungi and yeasts possessing a high killing
rate against Gram-positive and Gram-negative bacteria, but lower
toxicity toward mammalian cells (Kong et al., 2010). Due to its
antimicrobial activity, chitosan has attracted attention as a potential
natural food preservative (Prashanth & Tharanathan, 2007).