A soybean lysolecithin emulsion has small particle size and thermal, acid, and salt tolerance

• Lysolecithin allows for clear O/W type emulsification to form fine particles. • The lysolecithin emulsion provides excellent acid and salt resistance. • The emulsion particles formed by lysolecithin are less break down in the stomach. Lecithin, a natural emulsifier, has applications in various fields, including food processing. Whereas several studies have addressed the emulsifying properties and characteristics of emulsions prepared using lecithin, by focusing on single components of the highly purified phospholipids, information regarding enzymatically hydrolyzed lecithin remains lacking. Therefore, the characteristics and stability of emulsions at a level of quality suitable for food processing were evaluated. Emulsions were prepared by encapsulating medium-chain triglycerides (MCTs) using powdered soybean lecithin (SLP) and enzymatically hydrolyzed powdered soybean lecithin (SLP-lyso). Analysis of these emulsions showed that SLP-lyso formed emulsion particles smaller in size (below 100 nm) than SLP, allowing for the preparation of very clear emulsion solutions. In emulsion solutions subjected to repeated heating and cooling cycles, no separation of MCTs due to emulsion particle breakdown was observed, and the clarity of the solution remained high with the SLP-lyso preparation. Further, evaluation of the stability following dilution with an acidic or salt solution showed that SLP-lyso maintained a high degree of clarity and lacked turbidity. In addition, stability testing under simulated digestive conditions, i.e., fluids mimicking gastric (pH 1.2) and intestinal (pH 6.8) environments, showed that emulsion particles with SLP-lyso were not disrupted, and no emulsion breakdown was observed. Thus, enzymatically hydrolyzed lecithin, specifically SLP-lyso, offers significantly higher production efficiency and emulsion stability than non-enzymatically hydrolyzed lecithin.