Preserving high-protein fish by-products through silages and fermentates

Authors: BOWER, CYNTHIA; HIETALA, KATIE

Submitted to: Proceedings of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/8/2008
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: n Alaska, over three million metric tons of fish by-products are generated each year. However, due to the remote locations and seasonal nature of salmon fisheries, by-products are generally not fully utilized unless a fish meal plant is located nearby. Acidification is a common method for inhibiting microorganisms and promoting autolysis of animal tissues, thereby preserving perishable foods such as fish. In these studies, salmon by-products were stabilized using a variety of acidification methods, then the quality of the high-protein fish was evaluated. Hot-smoking technologies reduced the pH to 4.8, preserved proteins, and eliminated all “fishy” odors. Fermentation by lactic acid bacteria lowered the salmon by-products to pH 4.5 during 18 weeks of storage, but destroyed much of the fish protein. Fermentations using local agricultural discards such as potatoes as a carbohydrate source were not effective for stabilizing the pH of salmon. Ensilage through direct acidification using organic and inorganic acids decreased protein quality, but maintained a pH below 4.5 for 18 weeks. Alternative methods of preservation are needed to decrease the loss of valuable marine proteins and oils, and to provide salmon processors with environmentally sound options for adding value to by-products currently discarded as waste.