Cao Jiarui, Corstens Meinou, Schroën Karin
Laboratory of Food Process Engineering, Wageningen University and Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
Foods. 2024 Nov 26;13(23):3795. doi: 10.3390/foods13233795.
The protein transition motivates the use of plant proteins, but their application in food emulsions is challenging, especially when high concentrations of oil and salt are needed for formulation and sensory properties. In the present work, we connect the iso-electric point of two potato protein isolates (patatin-rich, POPI-200; protease inhibitor-rich, POPI-300) and a faba protein isolate (FPI) to the behavior in the bulk phase and at the interface, and relate this to the physical stability of 45 wt% oil-in-water (O/W) emulsions in the presence of NaCl at pH 4.0-7.0. In the absence of NaCl, a higher bulk viscosity was found at the iso-electric point (IEP), especially for the FPI. In the presence of NaCl, the viscosity of the POPI-200 solutions was highest, followed by POPI-300, and that of the FPI was lowest, irrespective of the pH. Both POPIs showed faster initial adsorption at the O/W interface in the absence of NaCl, and formed a more elastic layer compared to the FPI. For all proteins, salt addition leads to less elastic films. Interestingly, the interfaces were more elastic at a pH close to the IEP of the protein in the presence of NaCl. Both POPI-stabilized emulsions showed higher stability (smaller size and less oiling off) than the FPI-stabilized emulsions, which makes potato proteins relevant for food emulsion product formulation, even under high salt conditions.
蛋白质的转变促使人们使用植物蛋白，但其在食品乳液中的应用具有挑战性，尤其是在配方和感官特性需要高浓度油和盐的情况下。在本研究中，我们将两种马铃薯分离蛋白（富含马铃薯素的POPI - 200；富含蛋白酶抑制剂的POPI - 300）和一种蚕豆分离蛋白（FPI）的等电点与本体相和界面处的行为联系起来，并将其与在pH 4.0 - 7.0的NaCl存在下45 wt%水包油（O/W）乳液的物理稳定性相关联。在不存在NaCl的情况下，在等电点（IEP）处发现较高的本体粘度，尤其是对于FPI。在存在NaCl的情况下，无论pH如何，POPI - 200溶液的粘度最高，其次是POPI - 300，而FPI的粘度最低。在不存在NaCl的情况下，两种POPI在O/W界面处都表现出更快的初始吸附，并且与FPI相比形成了更具弹性的层。对于所有蛋白质，添加盐会导致形成弹性较小的膜。有趣的是，在存在NaCl的情况下，在接近蛋白质等电点的pH值下，界面更具弹性。两种由POPI稳定的乳液都比由FPI稳定的乳液表现出更高的稳定性（更小的粒径和更少的析油），这使得马铃薯蛋白即使在高盐条件下也与食品乳液产品配方相关。
