Physicochemical properties of plukenetia volubilis L. seeds and oxidative stability of cold-pressed oil (green nut oil)

Abstract

Cold-pressed oil from the seeds of Plukenetia volubilis L. (green nut oil, GNO) has been shown to be rich in n-3 fatty acid content, similar to flaxseed and perilla oils. These fatty acids are readily oxidized at high temperatures and under UV irradiation, limiting their potential applications. We therefore set out to clarify the physicochemical properties of green nuts. In addition, to explore means of the degradation process, we investigated the oxidation characteristics of GNO and the effects of oxidation on fatty acids. Results showed that GNO was stable up to 140°C and exhibited greater UV resistance than the other oils. This may be related to the 10% lower α-linolenic acid content of GNO, compared to the other oils, as well as the presence of γ- and δ-tocopherols. GNO was capable of tolerating a certain degree of heat processing.