Characterization of walnut oil extracted by supercritical CO2

Abstract

Walnut (Juglans regia L.) oil was extracted with compressed carbon dioxide (CO2) at the temperature 35 °C and the pressure 40MPa, for 30 min. It was studied the chemical composition of extracted oil: fatty acid profile, saponification and iodine index, acidity and peroxide values and compared to the cold pressed oil and oil obtained with hexane. The main FA was linoleic acid, followed by oleic acid and linolenic acid. Oxidative stability determined by PV revealed the modification of this value during storage for two months. Oil extracted by supercritical CO2 was more stable that cold pressed oil and hexane oil.