CHEMICAL AND NUTRITIONAL PROPERTIES OF PACIFIC OCEAN PERCH (SEBASTES ALUTUS) WHOLE FISH AND BY-PRODUCTS

Abstract

There is a growing interest in developing either food or feed ingredients from the large volumes of Pacific Ocean perch (POP) by‐products produced in Alaska. Determining the chemical composition of POP by‐products is fundamental for developing novel ingredients using these materials. The objective of this study was to chemically characterize POP and its by‐products. Triplicate samples of fresh POP whole fish, heads, frames and viscera were obtained from a commercial seafood processor in Alaska, and each replicate sample was individually analyzed for moisture, lipid, protein, ash, amino acid and mineral contents, fatty acid profile, lipid classes, pH, protein solubility, color, volatile amines and sodium dodecyl sulfate polyacrylamide gel electrophoresis of the proteins. The lipid and protein contents of the POP samples were 7.8 and 17.9% for whole fish, 10.5 and 15.2% for frames, 9.3 and 14.9% for heads, and 13.5 and 11.3% for viscera, respectively. Frames, heads and whole fish had ash values of 6.0, 6.7 and 4.3%, respectively. From the amino acid profiles, the values for lysine ranged from a low value of 7.3% for heads to a high value of 8.3% of total amino acids for frames. Methionine values ranged from 3.2 to 3.4% for all tissues. Frames and heads had high values for calcium and phosphorus, while viscera had the highest levels of iron. The analysis of fatty acids indicated high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with EPA/DHA ratios of approximately 2 for all tissues. Results indicated that the protein fraction of POP by‐products was of high quality, and its lipids were a valuable source of omega‐3 fatty acids. PRACTICAL APPLICATIONS This paper is the first examination of the chemical and nutritional properties of Pacific Ocean Perch (POP). There are fish processors that process substantial volumes of POP; however, the byproduct is seldom further processed into unique products. Processors could segregate POP byproducts and use this material to make products such as oils with a unique fatty acid profile as well as a distinctive color. Likewise single species POP byproduct meals could be produced and possibly fill niche market needs as food and feed ingredients.

Chemical Composition of Black Rockfish (Sebastes Melanops) Fillets and Byproducts

“…Monounsaturated fatty acids (MUFA) were the most abundant class of FA for both black rockfish heads and livers. Oleic acid (18:1ω9 cis ) was the predominant MUFA in all three tissues as it has also been observed for other northern rockfish species (Bechtel et al. 2009; Oliveira et al.…”

“…The SAT in black rockfish fillets (159 mg/g oil or 26.1%) was in agreement with levels of SAT reported in giant grenadier (27.7%), arrow‐tooth flounder (25.7%) and walleye pollock (27.6%) (Oliveira and Bechtel 2006). For heads, the palmitic acid content (127 mg/g oil) was slightly higher than that of pink salmon (12.4%), but similar to that of walleye pollock (16.8%) and Pacific Ocean perch heads (17.1%) (Bechtel et al. 2009; Oliveira and Bechtel 2005).…”

“…(2009). In Pacific ocean perch ( S. alutus ) heads, lipid (11%) and ash (6.7%) contents are higher than for the black rockfish, while moisture (67.7%) content is lower (Bechtel et al. 2009).…”

“…For yelloweye rockfish livers (Oliveira et al. 2009) and for Pacific Ocean perch viscera (Bechtel et al. 2009), the lipid content reported was 30.0 and 13.5%, respectively.…”

“…This trend was also reflected in the sum of SAT found in all three tissues. Palmitic acid was also the most abundant SAT found in Pacific Ocean perch heads and viscera, and also yelloweye rockfish heads and livers (Bechtel et al. 2009; Oliveira et al.…”