Surface Activities of Aqueous Solutions of Soy Lysophospholipid/ Fatty Acid Monoglyceride Mixtures

Abstract

Various mixtures of soy lysophospholipids (SLPs) and fatty acid monoglycerides (MGs) were examined for properties and surface activities of their aqueous solutions. The SLPs used were mixtures of mono-and diacylphospholipid (MDPL) and the lysophosphatidylcholine (LPC) purified form of SLP.(1) MGs were solubilized with SLPs, and their solubility increased with lysophospholipid content. Monostearin was solubilized to the greatest extent among the C18 fatty acid MGs examined. An aqueous solution of an SLP/MG mixture was relatively stable under acidic and salt conditions.(2) The water solubility of LPC/monostearin mixtures was altered by incubation at room temperature, and micellar transformation was observed to occur under an electron microscope.(3) Decrease in surface tension of the mixture was proportional to the extent of unsaturation of the C18 fatty acid of MG, and for mixtures containing the medium chain acid MG, maximum decrease in surface tension (25.5 mN/m) was observed.(4) Aqueous solutions of SLP/MG mixtures showed significant immersion and adhesion wettability when MGs consisted of polyunsaturated and/or medium chain fatty acids.(5) Mixtures of SLP/MG were more effective for O/W emulsification of vegetable oil compared to ordinary soy phospholipids/MG. Emulsions with SLP/MG mixtures were stable under acidic and salt conditions when SLP contained over 50% (wt/wt) LPC.(6) Aqueous solutions of MDPL/MG mixtures showed excellent dispersibility when MDPL contained more than 40% lysophospholipids. The betha-carotene solubilizing ability of SLP decreased on adding monostearin. The above results show that suitable blend of SLP/MG can be prepared using various mixtures for specific purposes as a safe and natural surfactant.