Lipase activity was measured using p-NPB as a substrate. The method was modified from the previously described by Kim et al. Briefly, an enzyme buffer was prepared by the addition 30 uL of solution of porcine pancreatic lipase (2.5 mg/mL in 10 mmol/L morpholinepropanesulphonic acid and 1 mmol/L ethylenediamine tetraacetic acid, pH 6.