|Bett Garber, Karen|
Submitted to: Food Science and Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2017
Publication Date: 5/16/2017
Citation: Bechtel, P.J., Bland, J.M., Bett Garber, K.L., Grimm, C.C., Brashear, S.S., Lloyd, S.W., Watson, M.A., Lea, J.M. 2017. Chemical and nutritional properties of channel and hybrid catfish by-products. Food Science and Nutrition. doi:10.1002/fsn3.483.
Interpretive Summary: This research is part of an ongoing effort to increase utilization and value of under utilized fish species and their respective byproducts. Channel and hybrid catfish are the most abundant aquaculture species grown in the United States. There are few value added products made from catfish byproducts. Understanding the chemical composition and nutritional value of catfish and its byproducts is the first step to promote development of value-added products from these raw materials. Comparable channel and hybrid byproducts are similar in composition; including % moisture, lipid, ash and protein, fatty acid, and amino acid profiles. There were major differences in the composition of different byproduct parts with the skin being the most different with a lower lipid content and a distinctive amino acid profile. All channel and hybrid byproducts had high % lipid values between 9.3% and 21.6%. The catfish off-flavor compound, geosmin, was present in all byproduct samples at concentrations below 1 ppb. Results from this study will be used in the development of new value added products from catfish byproducts.
Technical Abstract: In the past channel catfish (Ictalurus punctatus) accounted for most of the aquaculture reared fish; however, hybrid catfish (Ictalurus punctatus X Ictalurus furcatus) now account for an ever increasing percent of aquaculture reared catfish. The objective of this study was to chemically characterize both channel and hybrid catfish parts; including heads, frames, viscera, skin and fillet trimming. Triplicate samples of channel and hybrid catfish byproduct parts were obtained from a large commercial catfish processor in Mississippi and analyzed for percent moisture, lipid, protein, ash, and their amino acid and fatty acid profiles determined. The content of the off flavor compounds, 2-Methylisoborneol (MIB) and geosmin were also determined. The lipid content of samples were 13.6 % and 10.0 % for channel and hybrid skins, 17.7 % and 21.4 % for channel and hybrid viscera, 20.0 % and 19.1 % for channel and hybrid frames, and 9.7 % and 9.3 % for channel and hybrid heads. The protein content of samples ranged from a high of 22.8 % for channel catfish skins, to a low of 13.4 % for channel frames. Low levels of geosmin, less than 1 ppb, were detected in the byproduct samples, while no MIB was detected. Palmitic, oleic, and linoleic acid comprised approximately 80 % of the fatty acids in the byproduct tissues. The amino acid profiles indicated the catfish trim had high levels of lysine and methionine and other essential amino acids. Results from this study will be used in the development of new value added products from catfish byproducts.