Location: Food Processing and Sensory Quality Research
2019 Annual Report
Accomplishments
1. Method development for measurement of catfish fillet texture. The sensory qualities of catfish fillets is of primary importance to the processor and consumer. Textural quality can be equal to taste for subsequent rejection or acceptance by the consumer, and may also create processing difficulties with variable filleting requirements. Therefore, texture of farm-raised catfish has received much interest and ARS researchers in New Orleans, Louisiana, have developed a method for quickly evaluating fillet texture. Differences between male and female catfish of raw and cooked fillets were evaluated using instrumental methods of texture determination. No differences were found between genders. However, gender differences were seen in comparisons of raw and cooked catfish. Two texture attributes were significantly different between raw and cooked for female catfish, but for male catfish, four attributes were significantly different. Since the gender of catfish fillets is not normally known at the processor or the consumer, knowledge of lack of differences between them should have a positive impact on overall product acceptance. Correlations between raw and cooked fillet texture may give guidance to further research of production methods.
2. Method development for spatial analysis of fat in catfish fillets. The compounds responsible for catfish off-flavor and yellow off-color are very soluble in fat, so the (spatial distribution map) of fat across the catfish fillet is important in understanding and treatment of the flavor and color quality problems. Past methods required large amounts of fillet that prevented a defined spatial mapping. Methods were also limited by the time for analysis. A new method that uses time-domain nuclear magnetic resonance (TD-NMR) was developed by ARS researchers in New Orleans, Louisiana, to overcome these limitations. The TD-NMR method allowed a smaller sample size to be analyzed, which provided a more focused map of the fat content within the fillet. Also, the analysis time was reduced from days in the previous method to seconds for each point in the map using the TD-NMR method. In addition, the new method was non-destructive, so samples could be utilized for other studies, such as color and possibly off-flavor analysis. The TD-NMR method can benefit researchers and processors with a rapid analysis (seconds) of fat content of the fillet. The spatial analysis of fat and its correlation with off-flavor or color can benefit flavor checkers and processors in deciding which fillet region is best for determining quality problems or how to more efficiently trim the fillet.
