Extraction of oil and phytosterols from the peach seeds and melon seeds by supercritical carbon dioxide

Plant sterols called phytosterols are important structural components of plant membranes. They have been known to have low-density lipoprotein (LDL) and total cholesterol lowering properties and reduce cardiovascular diseases. In this study, oils were extracted from the peach (Prunus persica) and melon (Cucumis melo) seeds by supercritical carbon dioxide. Principal phytosterols which are ß-sitosterol, stigmasterol and campesterol were investigated in these seeds. According to analysis ß-sitosterol was identified in peach seeds oil, both ß-sitosterol and stigmasterol were identified in melon seeds oil. The effects of temperature, pressure, flow rate of supercritical fluid, particle size and extraction time that are known as efficient parameters on supercritical extraction, on quantity of extracted oil and phytosterols were investigated. The extracted oils were analyzed with respect to phytosterols by Gas chromatography ? Mass spectrometry (GC-MS). Internal standard (5?-cholestane) was used to prevent experimental errors. The results indicate that the quantities of oil and ß-sitosterol extracted from peach seeds were optimal with amounts of 35.3 g/100 g seed and 1220 mg/kg seed respectively at 40 °C, 200 bar, 7 ml/min, 0.3 mm and 3 hours. Quantities of oil and phytosterols extracted from melon seeds were optimal with amounts of 36.8 g/100 g seed and 425 mg/kg seed (ß-sitosterol; 304 mg/kg seed, stigmasterol; 121 mg/kg seed) respectively at 33 °C, 200 bar, 6 ml/min, 0.4 mm and 3 hours. By means of extraction of oils which include phytosterols from seeds this is considered as a useful study for human health and economy.