Abstract Polysaccharide conjugates were water-extracted from low-grade green tea; this extract was designated as TPC-W. Various concentrations of TPC-W (0.5, 1.0, 1.5, 2.0, and 3.0 wt%) were then used as an emulsifier stabilize to oil-in-water emulsions prepared using medium chain triglycerides. The emulsion stabilized using 2.0 wt% TPC-W remained relatively constant during 10 days of storage at 25 °C, with the mean particle diameter (MPD) (d32) and zeta potential increasing from 1.8 to 2.4 μm and from −19.8 to −18.9 mV, respectively. The effect of metal ions (Na+, Ca2+, and Al3+) and the pH value on the stability of the 2.0 wt% TPC-W emulsions was also studied at 25 °C for 10 days. The system remained stable at Na+ concentrations between 0.10 and 0.50 mol/L and Ca2+ concentrations below 0.030 mol/L, with little change in the MPD (d32) of the emulsion droplets. When Al3+ was added to the emulsion system, the MPD (d32) of the emulsion changed significantly; the addition of 0.001 mol/L Al3+ increased the MPD (d32) from 2.2 to 5.8 μm. The MPD (d32) of 2.0 wt% TPC-W emulsions with pH values of 2.0–4.0 increased significantly during the storage period, but remained stable for emulsions in the pH range 5.0–8.0. The results revealed new applications of TPC-W extracted from low-grade green tea as an emulsifier.

中文翻译：

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金属离子和pH值对低档绿茶多糖结合物乳化性能的影响

摘要 从低档绿茶中提取多糖结合物；该提取物被命名为 TPC-W。然后使用各种浓度的 TPC-W（0.5、1.0、1.5、2.0 和 3.0 wt%）作为乳化剂，稳定使用中链甘油三酯制备的水包油乳液。使用 2.0 wt% TPC-W 稳定的乳液在 25°C 下储存 10 天期间保持相对恒定，平均粒径 (MPD) (d32) 和 zeta 电位从 1.8 到 2.4 μm 和从 -19.8 增加到 -18.9 mV，分别。还在 25 °C 下 10 天研究了金属离子（Na+、Ca2+ 和 Al3+）和 pH 值对 2.0 wt% TPC-W 乳液稳定性的影响。系统在 Na+ 浓度介于 0.10 和 0.50 mol/L 之间和 Ca2+ 浓度低于 0.030 mol/L 时保持稳定，乳液液滴的 MPD (d32) 几乎没有变化。当在乳液体系中加入Al3+时，乳液的MPD(d32)发生显着变化；添加 0.001 mol/L Al3+ 将 MPD (d32) 从 2.2 μm 增加到 5.8 μm。pH 值为 2.0-4.0 的 2.0 wt% TPC-W 乳液的 MPD (d32) 在储存期间显着增加，但在 pH 值范围为 5.0-8.0 时保持稳定。结果揭示了从低档绿茶中提取的 TPC-W 作为乳化剂的新应用。但在 5.0-8.0 的 pH 范围内乳液保持稳定。结果揭示了从低档绿茶中提取的 TPC-W 作为乳化剂的新应用。但在 5.0-8.0 的 pH 范围内乳液保持稳定。结果揭示了从低档绿茶中提取的 TPC-W 作为乳化剂的新应用。