Influence of water content and emulsifiers on the stability and texture of oleogel-emulsions

This study evaluated the impact of water and emulsifier additions on the oil binding capacity (OBC), texture properties, and stability of oleogel-emulsions. Oleogels were prepared using beeswax and glycerol monostearate (7:3) as the oleogelators (10 %) with soybean oil. The physical properties of emulsions were examined based on the different ratios of emulsifiers e.g., Phospholipon 90 G (P90 G), Soy Lecithin (SL), and Tween (T80) and water content. OBC test showed that 1.5 % P90 G and 10 % water emulsion had the highest value (86.85±1.0 %) at 7 days. The emulsion's OBC followed the trend: P90 G > SL > T80. However, the emulsion formulated with 0.5 % P90 G and 15 % water had the lowest firmness (0.38±0.05 N), toughness (0.61±0.12 N.mm), and adhesiveness (0.06±0.01 N.sec) and the highest spreadability (0.19±0.04 N.sec). Conversely, emulsion prepared with 0.5 % T80 and 10 % water showed the highest firmness, toughness, and adhesiveness and the lowest spreadability (2.18±0.32 N.sec). In addition, SL emulsion also showed higher values for texture properties while lower value for spreadability in a consistent way. Further PLM images showed that high concentration (2 %) of P90 G and SL with 5 % water were stable at 40 °C, while 2 % T80 were stable at any percentages of water. These findings suggest that P90 G emulsion is preferrable if the application focuses on spreadability and light texture, which do not need to hold a shape over time. Conversely, SL emulsions are more tough, which is essential in products that are exposed to external forces. These findings highlight the potential of these glycerol monostearate-based oleogel-emulsions as stable systems for various applications.