Characteristics and composition of tomato seed oil

Abstract

Tomato seeds were separated from dried pomace, and seeds were ground and extracted with hot petroleum ether. The extracted oil was degummed, neutralised and bleached, and then the physical and chemical characteristics of crude and purified oils were determined. Purification led to a decrease in acidity, colour, unsaponifiables, E^1%_1cm 232 and oxidative stability, and to an increase in smoke point and E^1%_1cm 270. The fundamental physicochemical properties of the oil were not affected by purification. Tomato seed oil was found to contain high levels of linoleic (54%), followed by oleic (22%), while the dominant saturated acids were palmitic (14%) and stearic (6%). Purification led to an increase in C18:2 trans, while the fatty acid profile of the oil remained unchanged, a- and ô-tocopherols were detected at levels of 202 and 1059 mg/kg; purification reduced tocopherol content to 161 and 898 mg/kg, respectively (β-sitosterol was found as the most predominant component of the sterolic fraction from tomato seed oil. A large percentage (16%) of cholesterol was detected. Other sterols found in percentages higher than 1.5% were campesterol, stigmasterol and Δ⁵-avenasterol. In addition, trace to minor amounts of 24- methylenecholesterol, brassicasterol, Δ⁷-campesterol, clerosterol, Δ^{7 24}-stigmastadienol, Δ⁷-stigmastanol, Δ⁷-avenasterol and erythrodiol were found. Sterol profile was not affected by purification.