Sunflower Seed Lipase: Extraction, Purification, and Characterization

Abstract A simple procedure for the extraction of the lipolytic activity from sunflower seed has been developed. Various conditions of extraction have been optimized in order to obtain maximum yield of lipase. A new lipase enzyme was purified by the fractional salt precipitation from the supernatant, dialysis on a cellulose membrane, and gel column chromatography on Sephadex G‐75. The lipase was monomeric, with an apparent M r of 22 kDa and a pI of 8, with the electrophoretic analysis. Kinetics of the enzyme activity versus substrate concentration showed typical lipase behavior, with K m and V max values of 1.33 mM and 555 U/mg. All triglycerides were efficiently hydrolyzed by the enzyme, but this showed a preference towards triglycerides of natural mono unsaturated fatty acids. The optimum temperature, pH, and incubation time for lipolytic activity were 50°C, 7.5, and 5 min, respectively. The stability of the sunflower lipase was investigated under operational and storage conditions. It was found that this enzyme preserved its lipolytic activity at temperatures between at 35–50°C, alkaline pH, and for a period of about four months.