Function of sucrose fatty acid esters as emulsifiers in plant-based beverages

Sucrose fatty acid esters (SEs) are non-ionic emulsifiers that contain sucrose as hydrophilic and fatty acid as hydrophobic moieties. SEs have been evaluated for safety by the FAO/WHO Joint Expert Committee on Food Additives, and are widely used in food industry, especially in beverage products. Because of their lower environmental impact, dairy ingredients for beverages are now replacing with plant-based ingredients. SEs have long been used to improve the emulsification stability of dairy products, but little is known about the emulsification stability of plant-based beverages.
In this study, we compared the emulsion stabilizing functions of SEs and monoglycerides (MGs) in beverages containing plant-based ingredients and investigated the optimal emulsifier formulation for plant-based beverages. SEs or MGs were added as an emulsion stabilizer to beverages with coconut oil substituted for milk fat, and storage tests were conducted to evaluate the emulsion stability. Our results showed that the SE-added group had almost no fat grains, whereas the MG-added group contained more fat grains, indicating that the SEs exhibit a high emulsion stabilizing effect even in beverages containing coconut oil, which is difficult to stabilize. As a side effect of SEs in dairy-based beverages, it has known that SEs inhibit the spore germination and growth of heat resistant, spore-forming bacteria (such as Moorella and Geobacillus spp.), which can survive through UHT or retort pasteurization and grow in dairy products stored in high temperature. Our preliminary results showed that SEs inhibit the growth of such bacteria in plant-based beverages such as oat milk and soy milk, as well as they do in dairy products. These results suggest that SEs can be applied as an emulsion stabilizer and growth inhibitor of spore-forming bacteria even in plant-based beverages.