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Dietary effects on growth, liver peroxides, and serum and lipoprotein lipids in rats fed a thermoxidised and polymerised sunflower oil
Author(s) -
SánchezMuniz Francisco J,
LópezVarela Sara,
GarridoPolonio Maria C,
Cuesta Carmen
Publication year - 1998
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199803)76:3<364::aid-jsfa951>3.0.co;2-e
Subject(s) - sunflower oil , chemistry , tbars , very low density lipoprotein , composition (language) , cholesterol , food science , sunflower seed , lipoprotein , thiobarbituric acid , linoleic acid , biochemistry , sunflower , medicine , endocrinology , biology , lipid peroxidation , fatty acid , agronomy , antioxidant , linguistics , philosophy
The effect on food intake, weight gain, liver lipid peroxides, lipemia and lipoprotein composition was determined in rats fed a diet with 15% sunflower oil used repeatedly for frying and containing ∽19% polar material (group 2). These dietary effects were compared over a 4 week study period with those found in rats fed a control diet that contained 15% unused sunflower oil with ∽5% polar material (group 1). Both groups had similar food and nutrient intakes (except for linoleic acid, significantly lower ( P <0·01) in group 2), yet the final weight gain and food efficiency and protein efficiency ratios were significantly lower in group 2. As a consequence of thermoxidised oil ingestion, liver homogenates from group 2 presented higher ( P <0·02) levels of thiobarbituric acid reactive substances (TBARS) Liver TBARS levels were significantly correlated ( P <0·01) with the amount of thermoxidised substances ingested. No treatment effect was found on VLDL lipid composition. However, the LDL fraction of group 2 animals appears enriched ( P <0·05) in total and free cholesterol. In group 2 rats, phospholipids, and total and esterified cholesterol were significantly increased ( P <0·05) in HDL. As a consequence of the changes in the lipoprotein composition, the amount of all forms of serum cholesterol, and serum phospholipids was significantly higher (at least P <0·05) while the amount of serum triacylglycerols remained unchanged in rats fed the used oil. HDL‐phospholipids were significantly correlated ( P <0·02) with the amount of thermoxidised compounds ingested. The increase in serum cholesterol and phospholipids, and in HDL‐cholesterol and HDL‐phospholipid concentration seens in group 2 rats may be a protective mechanism against the peroxidative stress produced by the ingestion of used sunflower oil. © 1998 SCI.