Effects Of Phospholipids On Soybean Quality

This research mainly studies the effect of phospholipids on the quality of soybean oil (without antioxidant), including effect on flavor reversion and color reversion in soybean oil. Soybean oil was heated at 60℃ to simulate the process of oil oxidation during the storage and consumption time, by analyzing smell changes of soybean oil in the process of heating to identify the initial time of flavor reversion. Phospholipids in soybean oil was separated through SPE-diol column and then quantified by HPLC-PAD, The phospholipids was respectively added to the soybean oil triglycerides, according to 0.5,1,5,10 times of its content in soybean oil, and then placed at 60℃ for the period determined. The effect of phospholipids in types and content was estimated by peroxide value, sensory evaluation and content changes of the great contributors to flavor reversion. Soybean oil and the one added with 0.1% phospholipids were kept at 110℃ for 14h. The effect of phospholipids on color reversion in soybean oil was speculated with compare color changes between the two samples.Soybean oil for 31 hours kept at 60℃ has been determined as the initial time of reversion flavor, which was confirmed by PV, sensory evaluation and volatile compounds analysis. The result of HPLC showed that PC, PE, PI were contained in soybean oil with the content of 23.6ppm,17.0ppm,14.4ppm respectively. (E)-2-Heptenal, (T)-2-Octenal, 2-pentylfuran were all contained in the samples of oil added with phospholipids. Analysis of PV, sensory evaluation and volatile compounds consistently showed that the influence of phospholipids category was not significantly different, while difference between was remarkable. When the addition was 0.5 times, phospholipids can maintain its flavor by inhibiting of oil oxidation; When it was greater than 1 times, would accelerate oil oxidation causing flavor reversion, the higher addition the more serious the aftertaste. Besides, color reversion of soybean oil was also influenced by phospholipids.0.1% phospholipids added to the oil not only made color reversion occur earlier but also deepened the degree of it.