Chemical characteristics and compositions of red pepper seed oils extracted by different methods

The present work was undertaken to study the physicochemical characteristics, fatty acid, phenolic and tocopherol compositions as well as the antioxidant activities of red pepper seed oils extracted using different methods (soxhlet, cold-pressing, supercritical-CO2 and microwave-assisted extraction process). The results showed that the red pepper seeds were (on a dry-weight basis): ash 3.05%, water 6.63%, oil 18.39%, protein 28.33%, and total carbohydrate 43.60%. In addition, the results revealed that the predominant fatty acids were linoleic, palmitic and oleic acids. The highest and lowest contents of linoleic acid (76.54%) were found in microwave-assisted (76.54%) and soxhlet (73.65%) extracted pepper seed oils, respectively. < Gamma>-tocopherol was the main tocopherol at 278.65 mg/100 g seed oil, followed by < alpha>-tocopherol and < delta>-tocopherol. Nevertheless, high content in total tocopherols was found in microwave extracted red pepper seed oils. The lowest and highest values of oxidative stability were 1.25 and 11.26 h for soxhlet and microwave-assisted extracted seed oils, respectively. Overall, the high antioxidant activities of microwave-assisted extracted seed oil suggest that it could be economically used as valuable natural products for industrial, cosmetic, and pharmaceutical utilizations.