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ARS Home » Research » Publications at this Location » Publication #221188
Title: Salmon By-product Storage and Oil Extraction

Author
item Wu, Ted
item Bechtel, Peter

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/27/2008
Publication Date: 12/15/2008
Citation: Wu, T.H., Bechtel, P.J. 2008. Salmon by-product storage and oil extraction. Food Chemistry. 111(4):868-871.

Interpretive Summary: The free fatty acid levels (FFA), fatty acids composition and antioxidant activity in extracted oil from aging pink salmon heads and viscera stored at two temperatures (6C and 15C) for four days were determined. The FFA values in raw salmon heads and viscera increased with storage time and temperature. The maximum FFA values were 63±6 g/kg of oil at 15C and 29±8 g/kg of oil at 6C, respectively. A significant difference (P< 0.05) from the starting material was noted at day 1 at both temperatures. Fatty acid composition data indicated no changes in the levels of long-chain omega-3 (eicosapentaenoic acid) fatty acids with storage time or temperature. The concentration of long-chain omega-3 EPA (C20:5 omega-3) ranged from 9.3 to 11.3 g/ 100g, docosapentaenoic acid (DPA; C22:5 omega-3) from 2.2 to 2.6 g/ 100g, and docosahexaenoic acid (DHA; C22:6 omega-3) from 12.3 to 13.1 g/ 100g. The antioxidant activity of the pink salmon oils (n=3) at day 0 was 0.89±0.15 micromole Torlox equivalent/g of oil. Significant decreases (P<0.05) from the starting material were noted on day 2 for 15C samples and day 3 for 6C samples. On day 4, antioxidant activity for 15C samples was 0.41±0.12 micromole Torlox equivalent/g of oil and 0.27±0.11 micromole Torlox equivalent/g of oil for 6C samples. Oil extracted from raw salmon heads and viscera remained a good source of long chain omega-3 fatty acids even after 4 days of raw material storage at 15C; however, fat soluble antioxidant activity was reduced and free fatty acid levels increased with increased raw material storage temperature and time.

Technical Abstract: The free fatty acid levels (FFA), fatty acids composition and antioxidant activity in extracted oil from aging pink salmon heads and viscera stored at two temperatures (6C and 15C) for four days were determined. The FFA values in raw salmon heads and viscera increased with storage time and temperature. The maximum FFA values were 63±6 g/kg of oil at 15C and 29±8 g/kg of oil at 6C, respectively. A significant difference (P< 0.05) from the starting material was noted at day 1 at both temperatures. Fatty acid composition data indicated no changes in the levels of long-chain omega-3 (eicosapentaenoic acid) fatty acids with storage time or temperature. The concentration of long-chain omega-3 EPA (C20:5 omega-3) ranged from 9.3 to 11.3 g/ 100g, docosapentaenoic acid (DPA; C22:5 omega-3) from 2.2 to 2.6 g/ 100g, and docosahexaenoic acid (DHA; C22:6 omega-3) from 12.3 to 13.1 g/ 100g. The antioxidant activity of the pink salmon oils (n=3) at day 0 was 0.89±0.15 micromole Torlox equivalent/g of oil. Significant decreases (P<0.05) from the starting material were noted on day 2 for 15C samples and day 3 for 6C samples. On day 4, antioxidant activity for 15C samples was 0.41±0.12 micromole Torlox equivalent/g of oil and 0.27±0.11 micromole Torlox equivalent/g of oil for 6C samples. Oil extracted from raw salmon heads and viscera remained a good source of long chain omega-3 fatty acids even after 4 days of raw material storage at 15C; however, fat soluble antioxidant activity was reduced and free fatty acid levels increased with increased raw material storage temperature and time.