Amino Acid, Fatty Acid, and Mineral Profiles of Materials Recovered from Rainbow Trout (Oncorhynchus mykiss) Processing By-Products Using Isoelectric Solubilization/Precipitation

• Published in: Journal of food science Vol. 72; no. 9; pp. C527 - C535
• Main Authors: Chen, Y.-C., Tou, J.C., Jaczynski, J.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01-11-2007; Institute of Food Technologists; Wiley Subscription Services, Inc
• Subjects: amino acid profile; Amino acids; Amino Acids - analysis; Animals; Biological and medical sciences; Chemical Precipitation; Dietary minerals; fatty acid profile; Fatty acids; Fatty Acids - analysis; Fish and seafood industries; fish processing by-products; Fish Products - analysis; Fish Proteins - chemistry; Food Handling - methods; Food industries; Food processing industry; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Isoelectric Point; isoelectric solubilization/precipitation; Lipids; mineral profile; Minerals - analysis; Nutritive Value; Oncorhynchus mykiss; protein recovery; Solubility; Trout; Edible fish; isoelectric solubilization/ precipitation; fish processing by-products; Trout; Materials; Lipids; Oncorhynchus mykiss; Solubilization; Fatty acids; Inorganic element; Profile; Protein; fatty acid profile; Vertebrata; Precipitation; Fish by product; Pisces; mineral profile; amino acid profile; protein recovery; By product
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2007.00522.x

Protein, lipid, and insolubles (bones, skin, scales, fins, insoluble protein, and more) were recovered from rainbow trout processing by‐products by means of isoelectric solubilization/precipitation at basic pH and acidic pH. Isoelectric solubilization/precipitation of the trout processing by‐products resulted in the recovery of protein that was higher (P < 0.05) in essential amino acids (EAAs), non‐EAAs, and total EAA/total AA ratio when compared to the processing by‐products. Basic pH treatments yielded a higher (P < 0.05) content of EAAs than the acidic pH treatments. Nutritional quality of the recovered protein was high based on EAAs meeting the FAO/WHO/UNU recommendations for adults. The presence of omega‐3 and omega‐6 fatty acids (ω‐3, ω‐6 FAs) and the ω‐3/ω‐6 ratio in the recovered lipids were similar to the trout processing by‐products, indicating that the pH treatments had no effect on these FAs. Ca and P contents of the processing by‐products exceeded the recommended dietary allowances (RDA), but Fe and Mg did not. Basic pH treatments yielded protein with the lowest (P < 0.05) amount of minerals and the highest (P < 0.05) amount of Ca, P, and Mg in the insolubles when compared to acidic pH. The isoelectric solubilization/precipitation of the processing by‐products effectively removed minerals from the recovered protein without removal of the bones, skin, scales, fins, and so on, prior to processing. The results indicated that isoelectric solubilization/precipitation, particularly at basic pH, permitted recovery of high‐quality protein and lipids from fish processing by‐products for human food uses; also, the recovered insolubles may be used in animal feeds as a source of minerals.