February 15-18, 2009 Washington State Convention Center Seattle ...

INNOVATIVE USES FOR UNDER-UTILIZED SALMON TISSUES IN ALASKA
Cindy Bower* and Katie Hietala
USDA Agricultural Research Service
PO Box 757200
Fairbanks, AK 99775-7200 USA
Cindy.Bower@ars.usda.gov
The increased utilization of high quality fish by-products is receiving more attention as processors look for ways to expand
their markets. Fish meals and specialized fractions that can act as palatability enhancers and attractants for aquaculture feeds
are an important use, but fish by-products might also attract interest as functional foods affecting vitality and health in humans.
Potential exists for innovative products enriched with high-value fish proteins and “omega-3s” obtained from non-fillet components
of fish. However, to ensure success, underutilized fish by-products must be safely preserved. In this study, heads from
pink salmon (Oncorhynchus gorbuscha) were smoke-processed and/or fermented using food-grade lactic acid bacteria (LAB),
and the resultant oils and tissues were characterized.
Preservation of ground salmon heads through pH reduction using LAB was found to confer antimicrobial activity against
Gram-negative bacteria. Control samples did not receive LAB inoculations, relying entirely on endogenous proteolytic enzymes
to break down the tissues without acidification. Bacterial cell counts and lactic acid concentrations were recorded as a
measure of LAB viability. All samples were analyzed for moisture, ash, and lipid composition. Control samples were unable to
prevent spoilage of salmon by-products, whereas fermented salmon tissues stabilized at pH 4.5 for 120 days.
Oils extracted from smoked salmon heads retained valuable long-chain polyunsaturated fatty acids (PUFAs) in quantities equal
to frozen controls despite the high temperatures (95 °C) and extended heating times (5 hours) associated with smoking fish.
Additionally, these smoke-processed oils contained fewer products of oxidation than their unprocessed counterparts, suggesting
that natural antioxidants are imparted during the smoking process.
Salmon heads were also preservedusing a combination of smoke-processing and acidification with LAB. Wood smoke contains
com-pounds that lower the pH of salmon tissues. A further decrease resulted from LAB addition.
Increased utilization of processing discards promises environmental and economic benefits while con-serving valuable fish
resources.
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