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International Food Research Journal 18(4): 1303-1308 (2011)
1*
Seneviratne, K.N.,
1
Kotuwegedara, R.T. and
2
Ekanayake, S
1
Department of Chemistry, University of Kelaniya, Kelaniya, Sri Lanka
2
Department of Biochemistry, Faculty of Medical Sciences University of Sri
Jayawardenapura, Nugegoda, Sri Lanka
Serum cholesterol and triglyceride levels of rats fed with consumer
selected coconut oil blends
Abstract: Double blends were prepared by mixing copra oil (CO) with seed oils of Brassica juncea (BO),
Madhuca nerifolia (MO) and Sessamum indicum (SO) in different volume proportions. The consumer-acceptable
oil blends were selected based on the opinion of a panel of consumers about the palatability and other physical
properties of French fries prepared using the oil blends. The effect of the selected oil blends on serum lipid
parameters of Wistar rats was examined. The serum levels of total cholesterol, LDL and triglycerides decreased
and the serum levels of HDL increased signifcantly in rats fed with selected oil blends, when compared to those
fed with coconut oil. The benefcial effects on lipid parameters of the rats fed with the oil blend containing the
seed oil of BO (40%) and CO (60%) were closely comparable with those of the rats fed with soybean oil. The
results recommended that it could be helpful to prepare essential fatty acid-rich nutritional oil blends based on
CO in industrial scale.
Keywords: Coconut oil, soybean oil, oil blends, total cholesterol, HDL/LDL, triglycerides
Introduction
Coconut oil is the main fat of choice in many
Asian countries. Apparently, the common method
of preparation of coconut oil is by pressing dried
coconut kernel. As a result, the oil prepared by this
method is known as copra oil. It is well-known that the
composition of the saponifable fraction of edible oil
has a profound effect on serum lipoprotein cholesterol
and triglyceride levels (Harris, 1989; Grundy and
Denke, 1990; Kris-Etherton and Shaomei, 1997). The
results of these studies indicate that saturated fatty
acids increase the plasma total cholesterol and LDL-
cholesterol concentrations, whereas polyunsaturated
fatty acids lower these parameters. Coconut oil
contains up to 93% of saturated fatty acids. However,
the important feature of coconut oil is that it is
responsible for increasing serum HDL cholesterol
concentrations more profoundly than other sources of
saturated fat (Quig and Zilversmit, 1989; Carlson and
Kottke, 1990). One noticeable drawback of coconut
oil is due to its low level of essential fatty acids, with
the percentage weight of linoleic acid ranging from
1.0 to 2.6 (Dale and Meara, 1955). Therefore, blending
coconut oil with other edible oils containing higher
percentages of polyunsaturated fatty acids is suggested
as a convenient way of improving the essential fatty
acid content and associated nutritional and health
properties of coconut oil. Blended oils containing
coconut oil with groundnut oil or olive oil are proven
to be responsible in reducing of LDL oxidation and
enhancing hepatic antioxidant enzymes activity in
rats (Nagaraju and Belur, 2008). Recent reports also
indicate that blending of coconut oil with soybean
or sunfower oil improves hypolipidemic effects
(Chandrashekar et al., 2010). On the other effort,
improvement of the polyunsaturated fatty acid levels
by blending soybean oil, sunfower oil and faxseed
oil also results in benefcial effects on the serum lipid
profles of rats fed with a hypercholesterolemic diet
(Ramadan et al., 2009).
When the oil blends are prepared, it is important
to check the consumer acceptation about such blends
formulation. Even though the blending effort of
coconut oil with other edible oils has been reported
extensively, these studies do not indicate the signifcant
information about the consumer feedback especially
on the sensory evaluation. In addition to the nutritional
properties, the ultimate consumer acceptability of oil
blends depends on the organoleptic properties and
the physico-chemical properties of food prepared
using such oil blends. In order to reduce the cost of
production of coconut oil blends, it is also important
to use polyunsaturated oils that are easily available
in the coconut growing countries. In the present
study, sixteen oil blends were prepared with different
proportions of coconut oil and three other easily and
cheaply available edible oils. The hypolipidemic
effects of the consumer selected oil blends among the
prepared oil blends were investigated using Wistar
rats.