Optimization of degumming process for soybean oil by phospholipase B

Background: Enzymatic degumming, the 'EnzyMax® process', in which a phospholipase (type A₁, A₂ or B) was used to convert nonhydratable phospholipids into their hydratable forms. Compared with conventional methods, enzymatic degumming offers a safe biological route and eco-friendly solution to industrial processes. To date, only phospholipases A₁ and A₂ have been used for enzymatic oil-degumming. In this study, phospholipase B from Pseudomonas fluorescens BIT-18 was applied for the first time in soybean oil degumming. Results: Three major factors (temperature, pH and PLB dosage) were screened out through Plackett-Burman design. Then, response surface modeling combined with central composite design and regression analysis were employed for optimization of the final degumming process. The optimum conditions for the minimum residual phosphorus content in the oil were achieved at 40 °C, pH 4.7 and with PLB dosage of 500 U kg^-1. Under optimal conditions, the residual phosphorus content decreased to 4.9 mg kg^-1, which was comparable with predicted response values. Conclusion: These results suggested that Plackett-Burman design combined with response surface modeling were proved effective in determining the optimum soybean oil degumming conditions. The results also revealed that phospholipase B from Pseudomonas fluorescens BIT-18 was a good candidate for degumming various vegetable oils.