Ashleigh Macdonald

Research Interests

Ozone-Mediated Control of Food Spoilage and Food-Borne Pathogens’. 

Post-harvest produce is subject to contamination by food safety and food spoilage bacteria. Ozone is a reactive chemical species which can kill a broad range of micro-organisms; therefore, it could be used to control contamination in the food industry. Anacail Ltd have developed an ‘in-pack’ ozone system and this has been shown to reduce the population of micro-organisms in post-harvest produce, however some micro-organisms survive.

The aim of my project is to investigate the effectiveness of ozone treatment specifically against bacteria, that’s survival could have implications for the food industry, by investigating factors that are hypothesised to aid their survival. It is speculated that hydrogen peroxide has a similar effect against bacteria to ozone, therefore it is hypothesised that bacteria which are more tolerant to hydrogen peroxide will be more tolerant to ozone. It is also speculated that bacteria may enter into a reduced state of viability to survive.

Bacteria are hypothesised to survive if they are in a location on post-harvest produce which is inaccessible to ozone. The ability of bacteria to exist in the potentially altered microbial community of post-harvest produce after ozone treatment will also be investigated.