Immobilization of phospholipase A <inf>1</inf> and its application in soybean oil degumming
Yu, D., Jiang, L., Li, Z., Shi, J., Xue, J., Kakuda, Y. (2012). Immobilization of phospholipase A 1 and its application in soybean oil degumming. Journal of the American Oil Chemists Society (JAOCS), [online] 89(4), 649-656. http://dx.doi.org/10.1007/s11746-011-1943-4
Phospholipase A 1 (PLA 1), or Lecitase® Ultra, was immobilized on three different supports, calcium alginate (CA), calcium alginate-chitosan (CAC), and calcium alginate-gelatin (CAG), and crosslinked with glutaraldehyde. The results indicated that PLA 1-CA retained 56.2% of the enzyme's initial activity, whereas PLA 1-CAC and PLA 1-CAG retained 65.5 and 60.2%, respectively. Compared with free PLA 1, the optimal pH of immobilized PLA 1 shifted to the basic side by 0.5-1.0 pH units and the pH/activity profile range was considerably broadened. Similarly, the temperature-optima of PLA 1-CAC and PLA 1-CAG increased from 50 to 60 °C, and their thermal stability increased with relative activities of more than 90% that covered a wider temperature range spanning 50-65 °C. In a batch oil degumming process, the final residual phosphorus content was reduced to less than 10 mg/kg with free PLA 1, PLA 1-CAC and PLA 1-CA in less than 5, 6 and 8 h respectively while PLA 1-CAG was only able to reduce it to 15 mg/kg in 10 h. When the PLA 1-CAC was applied in a plant degumming trial, the final residual phosphorus content was reduced to 9.7 mg/kg with 99.1% recovery of soybean oil. The recoveries of immobilized PLA 1-CAC and activity of PLA 1 were 80.2 and 78.2% respectively. Therefore, it was concluded that PLA 1-CAC was the best immobilized enzyme complex for the continuous hydrolysis of phospholipids in crude vegetable oils. © AOCS 2011.