Chemical and nutritional properties of channel and hybrid catfish byproducts

The objective of this study was to chemically characterize both channel and hybrid catfish parts including heads, frames, viscera, skin, and fillet trimming mince. Triplicate samples of channel and hybrid catfish byproduct parts were obtained from a large commercial catfish processor and analyzed for percent moisture, lipid, protein, ash, and amino acid and fatty acid profiles were 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, <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 that the catfish mince 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.