SURFACE-ACTIVITY OF THE LIPID PRODUCTS HYDROLYZED WITH LIPASE AND PHOSPHOLIPASE A-2

We examined the in vitro surface activity, immersional wettability and adhesional wettability shown by aqueous solutions of soy lysophospholipid (SLP)/monoglyceride (MG)/fatty acid (FA), SLP/FA and SLP/MG, and found that many lipid mixtures showed significant surface activity when their MG and FA components consisted of polyunsaturated FA and/or medium chain FA. The more unsaturated the FA, the higher the surface activity. A mixture of SLP/medium chain fatty acid MG (medium chain MG)/medium chain FA showed the highest surface activity, and was comparable to an Aerosol-OT surfactant, the most effective wetting agent. SLP/polyunsaturated FA monoglyceride (polyunsaturated MG)/polyunsaturated FA, SLP/medium chain FA, and SLP/polyunsaturated FA, SLP/medium chain MG, and SLP/polyunsaturated MG also showed a high degree of activity. Wettability decreased rapidly when the amount of saturated, long chain FA moieties increased. It is recognized that the degrees of unsaturation and the chain length of FAs in the lipid mixtures have a decisive influence on surface activities. Higher ratios of MG and FA to SLP gave higher activity; and solubilizers such as bile salts were necessary to dissolve them in water.