Biological method for extracting fish oil from salmon by-products.

Abstract

The invention relates to a biological method for obtaining fish oil from salmon by-products. The by-products are cleaned, slow-frozen to a core temperature of -20 ± 1°C, partially thawed at 10–15°C, and ground while still cold. The substrate is mixed with water, briefly heat-treated to reduce intrinsic enzyme activity, and then hydrolyzed at natural pH by a mixture of bromelain, papain, and bacterial-derived protease at 40–65°C. After hydrolysis is stopped, the liquid is separated by two consecutive cold centrifugation stages at 4°C, with the second stage at a higher rate than the first, to recover the oil and separate the remaining water. The oil can be further dehydrated using anhydrous Na2SO4 and deodorized at reduced pressure at 45–60°C. The focus of the solution is the combined sequence of pre-freezing / freezing / grinding, hydrolysis with a triple protease system at natural pH, and two-stage cold separation.