球磨-酯化复合改性槟榔芋淀粉对Pickering乳液形成的影响

为了提高淀粉颗粒的乳化能力,以球磨-酯化复合改性槟榔芋淀粉为颗粒乳化剂,大豆油为油相,制备水包油型Pickering乳液。采用激光粒度仪、研究级正置显微镜、流变仪等对Pickering乳液外观、液滴粒径、显微形态及动态流变特性进行表征,考察淀粉颗粒质量浓度(1、5、10、20、30mg/mL)和油相体积分数(10%、20%、30%、40%、50%)对乳液稳定性和流变特性的影响。研究发现:增加颗粒质量浓度导致乳化相体积增加,液滴粒径减小；随着油相体积分数的增加,乳化相体积增加,液滴粒径增大。当颗粒质量浓度为20mg/mL,油相体积分数为40%时,乳液的乳析现象明显改善。球磨-酯化复合改性槟榔芋淀粉颗粒吸附在油/水界面,有效抵抗了液滴聚结,使乳液在储存30d后仍表现出良好的稳定性。流变特性表明:乳液内部存在弹性凝胶网络结构,随着颗粒质量浓度和油相体积分数的增加,液滴间堆积变得更紧密,从而增加了乳液黏度和凝胶强度,使其抵抗形变能力增强。球磨-酯化复合改性槟榔芋淀粉颗粒具有良好的作为Pickering乳液稳定剂的潜力。

Effect of Compound Modified Areca Taro Starch with Ball Milling and Esterification on Formation of Pickering Emulsions

To improve the emulsifying capacity of starch particles, soybean oil-in-water Pickering emulsions were prepared using compound modified areca taro starch with ball milling and esterification. The appearance, droplet size, microscopic morphology, and dynamic rheological properties of Pickering emulsions were characterized using laser scattering analyzer, research-grade upright microscope, rheometer, etc. The effects of starch particle mass concentration (1,5, 10,20, 30mg/mL) and oil phase volume fraction (10%, 20%, 30%, 40%, 50%) on stability and rheological properties of emulsion were investigated. Results indicated that the increment of the particle concentration increased the emulsified phase volume and decreased the droplet size. The emulsified phase volume and droplet size of Pickering emulsions increased with the increase of the oil phase volume fraction. When the particle mass concentration was 20mg/mL, and the oil phase volume fraction was 40%, the Pickering emulsion exhibited a great improvement in separation of emulsion. Compound modified areca taro starch particles were adsorbed at the oil/water interface and effectively resisted droplet coalescence, which led to good stability of the emulsion after 30 d storage. The rheological properties indicated that there was an elasticity-dominated gel-like network structure at inside of the emulsion. With the increasing of particle mass concentration and oil phase volume fraction, the emulsion droplets might pack in a denser manner, which increased the emulsion viscosity and gel-like strength, and enhanced its resistance to deformation. These findings demonstrated that compound modified areca taro starch with ball milling and esterification exhibited good potential as a stabilizer for Pickering emulsion stabilizer.