Location: Food Processing and Sensory Quality Research
2016 Annual Report
Accomplishments
1. Where best to check for off-flavor in catfish fillets. The project goal was to provide a set of standards for catfish flavor checkers to reduce the number of off-flavor fish from reaching the market. The object was to evaluate what part of the catfish fillet should be used to determine where best to check for off-flavor. ARS scientists from the Food Processing and Sensory Quality Unit of the Southern Regional Research Center in New Orleans, Louisiana processed catfish in to fillets and then each fillet was cut vertically and horizontally into 4 portions and analyzed for the off-flavor compounds 2-methylisoborenol (2-MIB) and geosmin, and fat content. Results indicated no trend was observed to support the hypothesis that portions of the fillet had higher concentrations of off-flavor compounds than other portions. There was little difference in the concentration of 2-MIB and geosmin within the fillet with current analytical techniques; therefore, no specific site within the fillet can be recommended for evaluation of off-flavors.
2. Improving the shelf life of fresh catfish fillets. Improving the shelf life of fresh catfish fillets is of great economic importance to catfish, retail food, and food service industries. Louisiana State University scientists collaborated with ARS scientists from the Food Processing and Sensory Processing Unit of the Southern Regional Research Center in New Orleans, Louisiana to evaluate the use of water soluble chitosan to improve the shelf life of refrigerated catfish fillets. Three treatments were prepared for this study: (1) 1% weak organic acid, (2) 0.5% chitosan (carbohyrdrate from shrimp shells) solution in 1% weak organic acid, and (3) 0.5% water soluble chitosan in water and water was used as a control solution. Fresh catfish fillets were tumbled with different solutions for 10 min in a vacuum tumbler and then the catfish fillets were refrigerated at 4 °C for 20 days. Results indicated catfish fillets treated with water soluble chitosan had the lowest lipid oxidation and inhibited yeast and mold counts more than the other treatments during the 20 days in refrigerated conditions. This study demonstrated that water soluble chitosan product, combined with vacuum tumbling, can be effective at reducing yeast and mold and lipid oxidation in catfish fillets during refrigerated storage.
