Enzymatic Degumming of Soybean Oil by Immobilized Phospholipase A1 on Plasma Surface Modified Chitosan Nanofibrous Membrane

The paper presents the enzymatic degumming of soybean oil by immobilization of phospholipase A1 (PLA1) on atmospheric plasma surface modified chitosan nanofibrous membrane. As evidenced by Scanning Electron Microscopy (SEM) images, chitosan nanofibers exhibited a number of properties indicating this polymer as a good enzyme carrier. Fourier Transform InfraRed (FT-IR) spectroscopy showed the reaction between the enzyme and functional groups of chitosan nanofibers. The properties of immobilized PLA1 were compared to free PLA1 in order to evaluate the possibility of using the immobilized enzyme for the degumming of soybean oil. The pH tolerance and thermal stability of the immobilized PLA1 were significantly improved. In addition, the immobilized PLA1 can be easily recovered and retained at 80% of its initial activity after 10 times of recycling. The enzymatic degumming process was carried out at 60°C and pH 6.0. The residual phosphorus content decreased to 8.6 mg/kg after 6 h, which is to meet oil safety standards and suitable for the physical refining of soybean oil.