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Determination of lipid oxidation products in vegetable oils and marine omega-3 supplements.

Halvorsen BL, Blomhoff R - Food Nutr Res (2011)

Bottom Line: However, PUFA are easily oxidizable and there is concern about possible negative health effects from intake of oxidized lipids.The contents of hydroperoxides and alkenals in omega-3 supplements are higher than in vegetable oils.After heating vegetable oils, a large increase in alkenal concentration was observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.

ABSTRACT

Background: There is convincing evidence that replacing dietary saturated fats with polyunsaturated fats (PUFA) decreases risk of cardiovascular diseases. Therefore, PUFA rich foods such as vegetable oils, fatty fish, and marine omega-3 supplements are recommended. However, PUFA are easily oxidizable and there is concern about possible negative health effects from intake of oxidized lipids. Little is known about the degree of lipid oxidation in such products.

Objective: To assess the content of lipid oxidation products in a large selection of vegetable oils and marine omega-3 supplements available in Norway. Both fresh and heated vegetable oils were studied.

Design: A large selection of commercially available vegetable oils and marine omega-3 supplements was purchased from grocery stores, pharmacies, and health food stores in Norway. The content of lipid oxidation products were measured as peroxide value and alkenal concentration. Twelve different vegetable oils were heated for a temperature (225°C) and time (25 minutes) resembling conditions typically used during cooking.

Results: The peroxide values were in the range 1.04-10.38 meq/kg for omega-3 supplements and in the range 0.60-5.33 meq/kg for fresh vegetable oils. The concentration range of alkenals was 158.23-932.19 nmol/mL for omega-3 supplements and 33.24-119.04 nmol/mL for vegetable oils. After heating, a 2.9-11.2 fold increase in alkenal concentration was observed for vegetable oils.

Conclusions: The contents of hydroperoxides and alkenals in omega-3 supplements are higher than in vegetable oils. After heating vegetable oils, a large increase in alkenal concentration was observed.

No MeSH data available.


Related in: MedlinePlus

Peroxide values (PV) (meq/kg) and alkenal concentrations (nmol/mL) before and after heating of 25 mL vegetable oil at 225°C for 25 minutes. The following products were tested: 1: Clearspring unrefined organic sunflower oil; 2: Coop Corn oil; 3: Coop Soy bean oil; 4: Eldorado Corn oil; 5: Eldorado Sunflower oil; 6: Fígaro olive oil, Premium quality; 7: Gaea Ecological Extra Virgin Olive oil; 8: Mills Soy bean oil; 9: Monini Extra Virgin Olive oil, Classico; 10: Odelia Norwegian cold-pressed rape-seed oil, for frying; 11: Vita Hjertego’ Optimal; 12: Ybarra Olive oil (glass bottle).*Result below LOQ.
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Figure 0001: Peroxide values (PV) (meq/kg) and alkenal concentrations (nmol/mL) before and after heating of 25 mL vegetable oil at 225°C for 25 minutes. The following products were tested: 1: Clearspring unrefined organic sunflower oil; 2: Coop Corn oil; 3: Coop Soy bean oil; 4: Eldorado Corn oil; 5: Eldorado Sunflower oil; 6: Fígaro olive oil, Premium quality; 7: Gaea Ecological Extra Virgin Olive oil; 8: Mills Soy bean oil; 9: Monini Extra Virgin Olive oil, Classico; 10: Odelia Norwegian cold-pressed rape-seed oil, for frying; 11: Vita Hjertego’ Optimal; 12: Ybarra Olive oil (glass bottle).*Result below LOQ.

Mentions: As can be seen from Fig. 1, heating vegetable oils increased PV in nine products and decreased PV in three products. The change of PV of heated oils was in the range 0.7–5.8 times compared to fresh oils. The formation of secondary lipid oxidation products, alkenals, increased in all vegetable oils that were heated. The increase in alkenal concentration of heated oils was in the range 2.9–11.2 times compared to the corresponding fresh oil. The maximum PV observed for heated oil was 4.6 meq/kg and maximum alkenal concentration was 538.2 nmol/mL. This corresponds to about 0.064% (w/w) peroxidized fatty acids and about 0.0054% alkenals in the oil. The four products with lowest alkenal content after heating were all olive oils, two of which were extra virgin olive oils and two were olive oils. Sunflower oils and soybean oils, along with one corn oil, had the highest alkenal content after heating.


Determination of lipid oxidation products in vegetable oils and marine omega-3 supplements.

Halvorsen BL, Blomhoff R - Food Nutr Res (2011)

Peroxide values (PV) (meq/kg) and alkenal concentrations (nmol/mL) before and after heating of 25 mL vegetable oil at 225°C for 25 minutes. The following products were tested: 1: Clearspring unrefined organic sunflower oil; 2: Coop Corn oil; 3: Coop Soy bean oil; 4: Eldorado Corn oil; 5: Eldorado Sunflower oil; 6: Fígaro olive oil, Premium quality; 7: Gaea Ecological Extra Virgin Olive oil; 8: Mills Soy bean oil; 9: Monini Extra Virgin Olive oil, Classico; 10: Odelia Norwegian cold-pressed rape-seed oil, for frying; 11: Vita Hjertego’ Optimal; 12: Ybarra Olive oil (glass bottle).*Result below LOQ.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3118035&req=5

Figure 0001: Peroxide values (PV) (meq/kg) and alkenal concentrations (nmol/mL) before and after heating of 25 mL vegetable oil at 225°C for 25 minutes. The following products were tested: 1: Clearspring unrefined organic sunflower oil; 2: Coop Corn oil; 3: Coop Soy bean oil; 4: Eldorado Corn oil; 5: Eldorado Sunflower oil; 6: Fígaro olive oil, Premium quality; 7: Gaea Ecological Extra Virgin Olive oil; 8: Mills Soy bean oil; 9: Monini Extra Virgin Olive oil, Classico; 10: Odelia Norwegian cold-pressed rape-seed oil, for frying; 11: Vita Hjertego’ Optimal; 12: Ybarra Olive oil (glass bottle).*Result below LOQ.
Mentions: As can be seen from Fig. 1, heating vegetable oils increased PV in nine products and decreased PV in three products. The change of PV of heated oils was in the range 0.7–5.8 times compared to fresh oils. The formation of secondary lipid oxidation products, alkenals, increased in all vegetable oils that were heated. The increase in alkenal concentration of heated oils was in the range 2.9–11.2 times compared to the corresponding fresh oil. The maximum PV observed for heated oil was 4.6 meq/kg and maximum alkenal concentration was 538.2 nmol/mL. This corresponds to about 0.064% (w/w) peroxidized fatty acids and about 0.0054% alkenals in the oil. The four products with lowest alkenal content after heating were all olive oils, two of which were extra virgin olive oils and two were olive oils. Sunflower oils and soybean oils, along with one corn oil, had the highest alkenal content after heating.

Bottom Line: However, PUFA are easily oxidizable and there is concern about possible negative health effects from intake of oxidized lipids.The contents of hydroperoxides and alkenals in omega-3 supplements are higher than in vegetable oils.After heating vegetable oils, a large increase in alkenal concentration was observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.

ABSTRACT

Background: There is convincing evidence that replacing dietary saturated fats with polyunsaturated fats (PUFA) decreases risk of cardiovascular diseases. Therefore, PUFA rich foods such as vegetable oils, fatty fish, and marine omega-3 supplements are recommended. However, PUFA are easily oxidizable and there is concern about possible negative health effects from intake of oxidized lipids. Little is known about the degree of lipid oxidation in such products.

Objective: To assess the content of lipid oxidation products in a large selection of vegetable oils and marine omega-3 supplements available in Norway. Both fresh and heated vegetable oils were studied.

Design: A large selection of commercially available vegetable oils and marine omega-3 supplements was purchased from grocery stores, pharmacies, and health food stores in Norway. The content of lipid oxidation products were measured as peroxide value and alkenal concentration. Twelve different vegetable oils were heated for a temperature (225°C) and time (25 minutes) resembling conditions typically used during cooking.

Results: The peroxide values were in the range 1.04-10.38 meq/kg for omega-3 supplements and in the range 0.60-5.33 meq/kg for fresh vegetable oils. The concentration range of alkenals was 158.23-932.19 nmol/mL for omega-3 supplements and 33.24-119.04 nmol/mL for vegetable oils. After heating, a 2.9-11.2 fold increase in alkenal concentration was observed for vegetable oils.

Conclusions: The contents of hydroperoxides and alkenals in omega-3 supplements are higher than in vegetable oils. After heating vegetable oils, a large increase in alkenal concentration was observed.

No MeSH data available.


Related in: MedlinePlus