Ozone degradation of off-flavors in catfish

In the United States aquaculture is a billion dollar industry. Aquaculture is essentially the production of aquatic organisms under controlled conditions. Although conditions are controlled to a certain degree, absolute control is not possible. This reason alone is a huge problem that can cost the industry millions of dollars a year. In catfish, geosmin and 2-methylisoborneol are two compounds are primarily responsible for imparting a musty/earthy off-flavor. Off- flavors are secondary metabolites of some blue-green algae and actinomycete bacteria. When present in fish tissue they create an undesirable taste. Different approaches have been used in order to alleviate the problem of catfish off- flavor, however as of yet no permanent solution has been found. Ozone, a very powerful oxidizer, is currently being used in a wide range of industries from wastewater to food. Previous research has shown that ozone is effective in eliminating off-flavors in water, while current research is exploring how it can further be applied. The purpose of this research is to determine the effects of ozone on off-flavors in catfish. Twenty grams was cut from fresh catfish fillets and spiked with 0 or 10 ppb of the off-flavor 2-Methylisoborneol. After being stored at 4°C for at least 12 hours the catfish was exposed to oxygen or ozone treatment for 0, 30 or 60 minutes. The concentrations were determined with SPME GC-MS analysis. Quality tests such as moisture, fat and color were also determined. The study indicates that oxygen and ozone treatments did differ, indicating that ozone treatment was successful in reducing catfish off-flavor. Moisture was unaffected, however color was significantly changed, while it was unclear if ozone was the cause of changes in fat