Combinational effects of acid and salt addition on colloidal, interfacial, and emulsifying properties of purified soybean oil bodies
Combinational effects of acid and salt addition on colloidal, interfacial, and emulsifying properties of purified soybean oil bodies
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DOI：
10.1016/j.foodhyd.2020.106213
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发表时间：
2021-02-01
影响因子：
10.7
通讯作者：
Matsumura, Yasuki
中科院分区：
文献类型：
--
作者：
Ishii, Toya;Matsumiya, Kentaro;Matsumura, Yasuki
大豆油储存细胞器（称为油体/油体（OB））是一种潜在的生态友好植物基乳化剂，而酸和盐的添加对OB乳化性能的综合影响仍不清楚。本研究的目的是调查的胶体，界面和乳化性质的OBs在乙酸和NaCl的存在下。从大豆种子中分离的纯化的OBs分散在10 mM的乙酸盐或磷酸盐缓冲溶液中，pH 4.0-7.0，不同的NaCl浓度在0和100 mM之间。没有添加NaCl，纯化的OBs在pH 4.0和4.5的静电排斥精细分散，而它们聚集在pH 5.0和5.5可能是由于小的净电荷。界面张力和界面粘弹性分析表明，强电荷的OBs在油水界面上的吸附速度较慢，形成的弹性吸附层较小;这种趋势可能是由于吸附态和未吸附态OB之间的静电吸附能垒所致。稳定的乳液在pH 4.0和4.5下轻微聚结而不添加NaCl，可能是由于相对少量的表面蛋白质负载。在所有其它测试的pH（4.0-7.0）和NaCl（0-100 mM）条件下，OB稳定的乳液由于改进的表面负载而对聚结稳定。这些结果表明，OBs可以作为一种潜在的生态友好的乳化剂，广泛适用于各种食品乳液与适当的酸和盐的配方。
Soybean oil-storing organelles called oil bodies/oleosomes (OBs) are a potential eco-friendly plant-based emulsifier, whereas combinational effects of acid and salt addition on emulsifying properties of OBs were still unclear. This study aimed at investigating colloidal, interfacial, and emulsifying properties of OBs in the presence of acetic acid and NaCl. The purified OBs isolated from soybean seeds were dispersed into 10 mM acetate or phosphate buffer solutions at pH 4.0-7.0 with different NaCl concentrations between 0 and 100 mM. Without added NaCl, the purified OBs were finely dispersed at pH 4.0 and 4.5 by electrostatic repulsion, whereas they aggregated at pH 5.0 and 5.5 probably due to small net charge. The NaCl addition caused screening of the electrostatic interaction between OBs and induced salting-in of OBs. Interfacial tension and interfacial viscoelasticity analyses showed that strongly-charged OBs tended to more slowly sparsely adsorb onto oil-water interface to form less elastic adsorbed layer; this tendency might result from electrostatic adsorption energy barrier between the adsorbed- and non-adsorbed OBs. The OB-stabilized emulsions slightly coalesced under at pH 4.0 and 4.5 without added NaCl probably due to a relatively small amount of the surface protein load. Under all the other tested pH (4.0-7.0) and NaCl (0-100 mM) conditions, the OB-stabilized emulsions were stable against coalescence because of the improved surface load. These results suggest that OBs can be widely applicable for various food emulsions as a potential eco-friendly emulsifier with the appropriate formulation of acid and salt.