Effects of stifled cooking on the quality and lipid-lowering potential of oils extracted from two species of pumpkin seeds (Citrullus lanatus and Cucumeropsis mannii)

Abstract

Background: Hyperlipidemia is a major risk factor for cardiovascular diseases. Cucumeropsis mannii and Citrullus lanatus commonly called pumpkin seeds or egussi, the oil-rich seeds, have already demonstrated hypolipidemic activity. In Africa, these seeds are popularly used in the preparation of local foods. During that thermal process, the fatty acid content of pumpkin seeds’ oils may be altered in their functionality. Thus, this work aims at studying the effect of stifled cooking on the quality and the lipid-lowering potential of oils’ extracts from Citrullus lanatus (CL) and Cucumeropsis mannii (CM).

Methods: The oils were extracted from the pumpkin seeds (raw and cooked) by a mixture of chloroform and methanol (2/1). The acid, iodine, peroxide and thiobarbituric acid value of the oils were assessed. For 28 days, the oils were subsequently administered by oral intubation to high-fat diet induced hyperlipidemic rats. At the end of the experimentation, the lipid profile, the markers of the hepatic and kidney function were determined.

Results: The oils extracted from raw CL and CM significantly reduced (p˂0,05) serum triglyceride, total cholesterol, Low Density Lipoprotein (LDL) cholesterol, uric acid, serum transaminases, creatinine, urea and increases the serum High Density Lipoprotein (HDL)cholesterol level relative to the oils extracted from cooked CM and CL. Moreover, the oil from cooked CL significantly (p<0.05) reduced some lipid profile and toxicity parameters (triglycerides and Alanine animotransferase) while increasing the serum HDL compared to the oil extracted from cooked CM. On the other hand, all the quality parameters of the raw materials followed the limits for vegetable oils, as opposed to cooked samples.

Conclusion: Stifled cooking affects the lipid-lowering potential of CM oil compared to that of CL oil.