Access Type

Open Access Dissertation

Date of Award

January 2014

Degree Type


Degree Name



Nutrition and Food Science

First Advisor

Kequan Zhou


Microbial safety of fresh fruits and vegetables is an increasing concern with any possible recall or outbreaks negatively affecting the entire industry. The interest in the development of active packaging has recently been steadily increasing due to significant concerns about environmental pollution caused by non-biodegradable packaging materials and consumer demand for high quality food products. Newly developed packaging materials and methods often have additional functional properties, such as antioxidant and antimicrobial properties.

In our study, the chitosan-gallic acid edible films and chitosan-essential oil coatings with antimicrobial activity, as well as active packaging with chlorine dioxide sachet were developed. The results show that the incorporation of gallic acid significantly increased the antimicrobial activities of the films against Escherichia coli, Salmonella typhimurium, Listeria innocua and Bacillus subtilis. Inclusion of 0.5 g/100 g gallic acid also significantly improved the mechanical and physical properties of chitosan film. For the chitosan-essential oil coatings, a combination of ࣙ 0.1% CAR or ࣙ 0.2% ECIN with a chitosan coating effectively reduced softening of fresh berries and decay by inhibiting microbial growth. The effect of chlorine dioxide (ClO2) gas on the safety and quality of blueberries was also studied and the results show that ClO2 treatment in active packaging improved the microbial safety of blueberries and reduced decay during storage without impairing the firmness.

Included in

Food Science Commons