Abstract: 【Objective】 Oxidative stability of oil is directly related to oil storage quality. Diacylglycerol, one of the trace components in soybean oil, affects the oxidative stability of oil. This article aims to study the influence of dilinolen on the oxidation stability of soybean oil and develop a new soybean oil antioxidant that will stabilize the oil quality and extend its shelf life. 【Method】 Experiments were carried out using original soybean oil (NSSO) and trace components-stripped soybean oil (TSSO) which was passed through chromatographic column. Dilinolen (LL) at different proportions of 0, 0.01%, 0.05%, 0.1%, 0.5%, 1.0%, and 2.0% was added to the soybean oils. A 30 ppm Chlorophyll B was also added into TSSO (Chlorophyll B/TSSO, W/W) and the control group was the soybean oil without dilinolen. All the samples were thoroughly mixed and stored at 25 oC and 1 700 lx under the open condition. Quality indicators of soybean oil were measured every seven days in the 6 weeks trial period according to the following methods. Iodimetry (GB/T5538-2005) was employed to evaluate peroxide value (POV) of samples. An oil oxidative stability instrument (Ominion, OSI-24）was employed to evaluate the oxidative stability index (OSI) of soybean oil using the GB/T21121-2007 method. Head-space gas chromatography and mass spectrum (GC/MS) were used to determine the composition and relative content of volatile aldehydes in the oils. Fatty acid composition was measured by gas chromatography spectrum. All assays were conducted in triplicate and variance was analyzed by IBM SPASS19.0. The means were compared using Duncan’s multiple range test.【Result】The results obtained during the 6 weeks trial period are as follows: The longer the storage time, the higher the POV value, indicating the increased oxidation of the sample, while the increased magnitude of POV values decreased with increasing amount of dilinolen. The OSI decreased with prolonged storage, reflecting the poor oxidative stability of the oils; OSI values were mitigated with the increase of the amount of LL; The reduced amplitude of OSI of TSSO was lower than that of NSSO at the same amount of dilinolen and storage time. The relative contents of volatile aldehydes in the oils were increased with prolonged storage time. The content of volatile aldehydes in oils with dilinolen added were lower than that of the control, which decreased with the increase of the amount of dilinolen added. The ratio values of unsaturated fatty acids to saturated fatty acids (U/S) decreased as storage time increased. During the same storage cycle, the U/S of the oil samples containing dilinolen was higher than that of the control group. The higher the amount of dilinolen added, the higher the linoleic content, and there was no significant change in the content of other fatty acids. 【Conclusion】 Under room temperature and light conditions, it is effective to inhibit the oxidation of soybean oil with the addition of dilinolen. The effect of dilinolen on TSSO is also significantly better than on NSSO.

Key words: dilinolein , soybean oil , oxidative stability , peroxide value , fatty acids , antioxidant