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Title:	The effect of repeated heating of frying oils on blood lipid profiles and malondialdehyde level in rats
Authors:	Emran Neda. (P49017)
Supervisor:	Halimah Abdullah Sani, Dr.
Keywords:	Blood lipids. Frying oils Epididymal adipose tissue
Issue Date:	17-Aug-2011
Description:	Fats and oils undergo changes during repeated heating when used as frying oil by formation of products that may pose health hazards. The aim of this research was to investigate the effects of five times repeated heating of palm olein (5-HPO) and corn oil (5-HCO) on blood lipid profiles, liver malondialdehyde T-bar level (MDA-Tbar), adipose tissue lipoprotein lipase activity (LPL), serum glutamic-oxaloacetictransaminase (GOT) and glutamic-pyruvic-transaminase (GPT) in comparison to nonheated palm olein (FPO) and non-heated corn oil (FCO) and without oil diet served as controls. Changes in the quality of palm olein and corn oil were measured after deepfrying of chicken meat for one to five times. Male Sprague dawley rats (n = 5) were fed normal rat diet supplemented with 15% w/w palm olein and corn oil (FPO, FCO, and 5-HPO, 5-HCO) for eight weeks. Blood samples were used for determination of lipid profile such as triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-Chol), low density cholesterol (LDL-Chol), GOT and GPT. Epididymal adipose tissue was obtained for measurement of LPL activity and liver was used for determination of MDA-Tbar level. Results showed that, colour, peroxide value and free fatty acid content of both oils were significantly increased (P<0.05) after repeated heating as the frying oil. Peroxide value in five times heated corn oil 5-HCO (17.7±1.9 meq/kg) was significantly higher than five times heated palm olein 5-HPO (11±0.6 meq/kg). The results in rats study showed that there was no significant difference (p>0.05) in the blood TG level between groups, although adipose tissue LPL specific activity was significantly increased (P<0.05) in rats treated with 15% FPO diet (10.24±0.81 U/mg), FCO (10.78±1.09 U/mg), five times heated 5-HPO (13.48±1.03 U/mg) and 5-HCO (12.98±0.78 U/mg). Blood TC level significantly increased (P<0.05) to 109.20 ± 0.73 mg/dl in rats treated with 5-HPO and 108.0±0.73mg/dl with 5-HCO. LDL-chol level was significantly increased (P<0.05) in 5-HPO treated (28.61±1.69 mg/dl) and in 5-HCO treated (26.94±1.04 mg/dl) rats compared to non-heated FPO (16.65±0.96 mg/dl) and non-heated FCO (13.05±3.6 mg/dl). Plasma HDL-Chol level was significantly decreased by heated 5-HPO (54.83±1.25 mg/dl) and 5-HCO (56.13±1.84 mg/dl). Liver MDA-Tbar level was significantly higher in rats treated with heated corn oil 5-HCO (14.14±0.35 nmol/g) compared to heated palm oil 5-HPO (12.56±0.29 nmol/g), non-heated FPO (4.62±0.14 nmol/g) and non heated FCO (5.96±0.06 nmol/g). Both serum GOT and GPT activities were significantly increased (P<0.05) in rats treated with 5-HPO and 5-HCO. In conclusion, changes in palm olein and corn oil quality by repeated heating as recycled frying oil may lead to harmful effects on blood lipid profiles and lipid peroxidation in liver.,Master
Pages:	159
Call Number:	QP751 .E467 2011
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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