Characterization of immobilized phospholipase A1 on magnetic nanoparticles for oil degumming application

Phospholipase A1 (PLA1) was immobilized onto magnetic Fe3O4/SiOx-g-P(GMA) nanoparticles. The properties of immobilized PLA1 were compared to free PLA1 in order to assess the feasibility of utilizing the immobilized enzyme for degumming of soybean oil. The immobilized PLA1 process retained 2066.67 μ/g activity with 64.7% immobilization efficiency. Compared to free PLA1 process, the immobilized PLA1 had a broader pH-activity profile of pH 4.5-6.5 and was remarkably stable at 45 °C-55 °C for 7 h. The optimum temperature for the immobilized and free PLA1 was 60 °C and 50 °C, respectively. After 10 cycles through the soybean oil degumming process at 55 °C, the immobilized PLA1 still possessed more than 80% of its initial activity. The water degumming process was carried out at 55 °C and pH 6.0. The residual phosphorus content was 9.6 mg/kg, which is to meet oil safety standard and suitable for the physical refining of soybean oil.

► The immobilized PLA1 showed a better stability in a broad range of the temperature and pH compared to the free PLA1. ► The optimum pH and treatment time of immobilized PLA1 was pH of 6.0 and 5 h ► The immobilized PLA1 can be reused 7 times without a significant loss of its activity.