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Title: OMEGA-3 FATTY ACIDS IN SALMON PRESERVED BY NATIVE ALASKAN METHODS

Author
item Bower, Cynthia
item Malemute, Charlene
item OLIVEIRA, A - UNIV OF ALASKA, FITC

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/6/2006
Publication Date: N/A
Citation: N/A

Interpretive Summary: Traditional Native Alaskan diets included salmon as a major source of n-3 long-chain polyunsaturated fatty acids (PUFA). However, in the last 250 years, profound changes have influenced the people of interior Alaska. Departure from ancestral dietary practices has led to a rise in obesity and Type-2 diabetes in Native youth. Increased consumption of long-chain PUFA has been linked to reduced risk of Type-2 diabetes in overweight individuals. The objective of this study was to preserve salmon by five different Native Alaskan methods, and then evaluate the status of n-3 fatty acids in each sample so that science-based recommendations could be made concerning food preservation choices. A survey was conducted to determine salmon consumption patterns and preservation techniques commonly used along the Yukon River of interior Alaska. Based on this information, salmon fillets (consumed by 100% of survey respondents) and heads (consumed by 95%) were chosen for study. The five most common preservation methods were identified as jarring (26%), smoking (22%), freezing (22%), pickling (13%), and salting (13%). The greatest quantity of n-3 PUFAs (82%) was retained when salmon fillets were either smoked or jarred. Other preservation methods were more destructive, with freezing, pickling, and salting retaining only 53%, 29%, and 24% (respectively) of the original n-3 PUFA content. Salmon heads contained over 300% more total fatty acids than fillets, as well as higher levels of n-3 PUFAs even after boiling.

Technical Abstract: Traditional Native Alaskan diets included salmon as a major source of n-3 long-chain polyunsaturated fatty acids (PUFA). However, in the last 250 years, profound changes have influenced the people of interior Alaska. Departure from ancestral dietary practices has led to a rise in obesity and Type-2 diabetes in Native youth. Increased consumption of long-chain PUFA has been linked to reduced risk of Type-2 diabetes in overweight individuals. The objective of this study was to preserve salmon by five different Native Alaskan methods, and then evaluate the status of n-3 fatty acids in each sample so that science-based recommendations could be made concerning food preservation choices. A survey was conducted to determine salmon consumption patterns and preservation techniques commonly used along the Yukon River of interior Alaska. Based on this information, salmon fillets (consumed by 100% of survey respondents) and heads (consumed by 95%) were chosen for study. The five most common preservation methods were identified as jarring (26%), smoking (22%), freezing (22%), pickling (13%), and salting (13%). Coho salmon (Oncorhynchus kisutch) fillets and heads were preserved using these common methods, then stored for 90-days before testing for n-3 long-chain PUFA. Lipids were extracted with a solvent mixture of isopropyl alcohol and hexane, and stored at -80 °C under a headspace of nitrogen. Fatty acids were converted to their methyl esters before being analyzed by gas chromatography. Moisture, ash, and protein values for each sample were also determined. Total fatty acids for smoked and jarred fillets were higher than for salted, pickled, or frozen samples. The greatest quantity of n-3 PUFAs (82%) was retained when salmon fillets were either smoked or jarred. Other preservation methods were more destructive, with freezing, pickling, and salting retaining only 53%, 29%, and 24% (respectively) of the original n-3 PUFA content. Salmon heads contained over 300% more total fatty acids than fillets, as well as higher levels of n-3 PUFAs even after boiling.