School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Department of Food Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632, China.
Molecules. 2018 Jun 26;23(7):1533. doi: 10.3390/molecules23071533.
Perilla seed protein (PSP) was extracted from defatted perilla seed meal and applied in oil-in-water (O/W) emulsions as an emulsifier. We investigated the influences of protein concentration (0.25⁻1.5 wt %), pH (3.0⁻9.0), NaCl concentration (0⁻350 mmol/L) and thermal treatment (70⁻90 °C, 30 min) on the physical characteristics of O/W emulsions, including volume-average diameter, ζ-potential, interfacial protein concentration, microstructure and so on. Results showed that increasing PSP concentration would decrease the and a 1.0 wt % PSP concentration was sufficient to ensure the stability of emulsion. Under pH 3.0⁻9.0, emulsions were stable except at pH 3.0⁻5.0 which was proximal to the isoelectric point (pH 4.5) of PSP. At high NaCl concentrations (250⁻350 mmol/L), the emulsions exhibited relatively lower absolute ζ-potential values and a large number of aggregated droplets. A moderate thermal treatment temperature (e.g., 70 °C) was favorable for the emulsion against aggregation and creaming. However, when 90 °C thermal treatment was performed, a clear layer separation was observed after 2 weeks storage and the emulsion showed a poor stability. The findings of this work are of great importance for the utilization and development of PSP as an emulsifier for food emulsions.
从脱脂紫苏籽粉中提取紫苏籽蛋白（PSP），并将其用作水包油（O/W）乳液的乳化剂。我们研究了蛋白质浓度（0.25⁻1.5wt%）、pH 值（3.0⁻9.0）、NaCl 浓度（0⁻350mmol/L）和热处理（70⁻90°C，30min）对 O/W 乳液物理特性的影响，包括体积平均粒径、ζ-电位、界面蛋白浓度、微观结构等。结果表明，增加 PSP 浓度会降低 和 ，而 1.0wt% PSP 浓度足以确保乳液的稳定性。在 pH 值 3.0⁻9.0 范围内，乳液是稳定的，除了在 pH 值 3.0⁻5.0 附近，接近 PSP 的等电点（pH 4.5）。在高 NaCl 浓度（250⁻350mmol/L）下，乳液表现出相对较低的绝对 ζ-电位值和大量聚集的液滴。适度的热处理温度（例如，70°C）有利于乳液防止聚集和分层。然而，当进行 90°C 热处理时，在 2 周储存后观察到明显的分层，乳液稳定性较差。本研究结果对 PSP 作为食品乳液乳化剂的利用和开发具有重要意义。
