State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047, Jiangxi, China.
Biopolymers & Colloids Research Laboratory, Department of Food Science, University of Massachusetts, Amherst, MA 01003, USA.
Food Res Int. 2018 Dec;114:30-37. doi: 10.1016/j.foodres.2018.07.062. Epub 2018 Aug 1.
Emulsion-based excipient foods were developed to improve the bioaccessibility of an important hydrophobic nutraceutical: quercetin. Protein-stabilized oil-in-water excipient emulsions were prepared using sodium caseinate, whey protein isolate, or soy protein isolate as an emulsifier. These emulsions were then mixed with powdered quercetin and heated to simulate a cooking process. The excipient emulsions had relatively small droplet sizes (d < 270 nm) and remained stable against coalescence after exposure to boiling (100 °C for 60 min). In particular, casein was shown to be better at adsorbing to oil-water interface and contributed to a more stable interfacial layer than the other two proteins. Quercetin was solubilized in the emulsions during heating, which may be attributed to dissolution in the oil phase and complexation with proteins. There were appreciable differences in quercetin bioaccessibility in excipient emulsions stabilized by different emulsifiers (≈74% for casein, 54% for whey protein, 22% for soy protein, and 58% for Tween). This study suggests that milk proteins may be natural alternatives to synthetic surfactants for forming stable excipient emulsions capable of enhancing nutraceutical bioaccessibility.
基于乳液的赋形剂食品被开发出来，以提高一种重要的疏水性营养保健品：槲皮素的生物利用度。使用酪蛋白酸钠、乳清蛋白分离物或大豆蛋白分离物作为乳化剂制备了蛋白质稳定的油包水赋形剂乳液。然后将这些乳液与粉末状槲皮素混合并加热，以模拟烹饪过程。赋形剂乳液的液滴尺寸相对较小（d<270nm），并且在暴露于沸腾（100°C 60min）后仍能保持稳定，不易聚结。特别是，酪蛋白被证明比其他两种蛋白质更能吸附到油水界面，并有助于形成更稳定的界面层。在加热过程中，槲皮素溶解在乳液中，这可能归因于在油相中的溶解和与蛋白质的络合。由不同乳化剂稳定的赋形剂乳液中槲皮素的生物利用度有明显差异（酪蛋白约为 74%，乳清蛋白为 54%，大豆蛋白为 22%，吐温为 58%）。本研究表明，牛奶蛋白可能是形成能够增强营养保健品生物利用度的稳定赋形剂乳液的天然替代品，替代合成表面活性剂。
