Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 26, 2008
Publication Date: N/A
Over half of the USA’s fish harvest is from Alaska. This results in over one million metric tons of fish-processing waste each year, much of which is discarded. Salmon make up about 9% of the catch and are widely recognized for their valuable oils, which contain high concentrations of long-chain n-3 polyunsaturated fatty acids (PUFA). However, the high-protein salmon tissues that remain after oil extraction are underutilized and may actually be discarded unless a fish meal plant is located nearby.
Heads from pink salmon (Oncorhynchus gorbuscha) typically contain 71% moisture, 14% protein, 9% lipid and 6% ash. After oil extraction the remaining tissue is not stable without further processing (such as acidification, freezing, or drying). When salmon heads were smoke-processed (75 °C, 5h) prior to removal of oil, moisture levels only decreased to 67%, which was not sufficient to prevent spoilage without an additional preservation step. However, when lactic acid bacteria (LAB) were added, together with a carbohydrate source such as sucrose, the salmon tissue decreased from pH 6.5 to pH 4.5 and retained that acidity when tested 60 days later. The smoked, fermented salmon material also acquired pleasant aroma and flavor characteristics.
Tissue from discarded salmon heads following oil extraction represents a valuable source of food-grade protein, which can be dried immediately or fermented using LAB for longer-term storage. Potential products from this fish-based material include high-protein crackers, salmon bouillon cubes, and powdered protein supplements.