The combination of starch nanoparticles and Tween 80 results in enhanced emulsion stability

In this work, we aimed to investigate the effect of the combination of starch nanoparticles (SNPs) and Tween 80 (TW) on the stability of oil-in-water emulsions. The emulsions prepared under different SNPs/TW ratios and different oil fraction values were characterized by means of photography, optical microscopy, laser particle size analysis, rheological measurement, quartz crystal microbalance analysis, and confocal laser scanning microscopy. At an oil fraction value of 0.4, the emulsions with a 3: 1 ratio of SNPs (1.5%, w/v) to TW (0.5%, w/v) exhibited excellent storage stability over a long period of 30 d, which was significantly better than the 2% TW stabilized emulsion and the 2% SNPs stabilized emulsion. Compared with the SNPs stable emulsions, the presence of TW decreased the emulsion droplets size, which was beneficial to reduce the aggregation of droplets. Emulsions co-stabilized by SNPs and TW can maintain good performance under harsh conditions. The results of quartz crystal microbalance analysis and isothermal titration calorimetry revealed non-covalent interactions between SNPs and TW. The results showed that SNPs and TW co-existed at the oil-water interface and improved the performance of the emulsion.