Two of the major dietary food sources of omega-3 fatty acids are flaxseed oil and
fish oil; the former being a rich source of PUFA (e.g. α-linolenic acid (α-LA)), while the
latter is a source of HUFA (e.g. eicosapentaenoic acid (EPA) and docosahexaenoic acid
(DHA)). In this study, palm oil, a commonly used vegetable oil that is widely available in
Asian and African countries, was blended with flaxseed (omega 3-PUFA) and fish oil
(menhaden oil) (omega-3 HUFA); respectively, to obtain blended oils that both contained
a 1: 4 ratio of omega-3 :omega 6 fatty acids. Rosemary extract (0.02% w/w) was added to
the oil blends to stabilize the oil during use for deep-fat frying. Eight hours of heating at
180 °C was used to determine the stability of omega-3 fatty acids and uptake from the
omega-3 enriched palm oil into fried potatoes. Lipid oxidation and thermal degradation
of the palm oil blends, along with retention of α-LA , EPA, and DHA were measure of
oil blends stability. Linoleic acid content in flax-palm oil blend did not change during
frying when in the presence of different antioxidant treatments. The α-LA content of
heated flax-palm oil blend was significantly reduced (P<0.05) after 8 hours of frying.
Meanwhile, linoleic acid and EPA content in the fish-palm oil blend revealed significant
(P<0.05) decreases in concentration after 8 hours of frying regardless of the presence of
antioxidant. The DHA concentration was significantly lower when present in the absence
of antioxidant (P<0.05). Totox significantly increased (P<0.05) in the blended oils after 8
hours of frying; albeit the extent of oxidation and thermal degradation was reduced when
rosemary extract was added. A significant uptake of omega-3 fatty acids in both the omega-3 PUFA (e.g. α-LA) and HUFA (e.g. EPA and DHA), respectively, occurred in
potatoes fried in the respective blended oils. Although omega-3 fatty acid uptake was
prevalent in potatoes fried in both blended oils, the effect of heating reduced the optimal
1:4 ratio of omega-3 :omega-6 to a 1:6-l :7 ratio. This loss in omega-3, relative to omega-
6, was attributed to thermal oxidation; a reaction not totally preventable by adding
antioxidants to the frying oils. These functional omega-3 enhanced oils when used to
process potatoes gave forth products that represented 1/10th suggested intake for
EPA+DHA and l/50th the daily requirement for α-LA . / Land and Food Systems, Faculty of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/32399 |
| Date | January 2007 |
| Creators | Soewono, Adri A. |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Rights | For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. |
Page generated in 0.0017 seconds