PDF(Pubmed)
Abstract：
In the current study, optimization of milk thistle protein extraction parameters was carried out in terms of purity and yield. In addition, the characterization of proteins isolated from milk thistle seeds was conducted. The optimal conditions for achieving the highest purity of protein (MTP) from milk thistle seeds were identified as extraction pH 9.47, temperature 30°C, and extraction time 180 min. Conversely, optimal values for overall protein yield (MTY) were determined at extraction pH 12, temperature 50°C, and extraction time 167 min. The proteins obtained under these two sets of conditions (MTP and MTY) demonstrated comparable oil absorption capacity (OAC), foaming, and emulsifying capabilities, as well as stability, aligning with findings from previous studies on seed protein. Both proteins had the highest protein solubilities at pH 11. Both proteins\' zeta potentials were closest to zero at pH 4, demonstrating their closeness to the isoelectric point. MTP and MTY had poorer antioxidant capabilities than the other protein isolates/concentrates. MTP and MTY contain high β sheet concentrations that might enhance thermal stability and lower the digestibility of proteins. In conclusion, the protein extraction process demonstrated a high potential for achieving both substantial yield and remarkable purity with some decent technological and functional properties, thus holding promise for various applications in diverse fields.
摘要：
在目前的研究中,从纯度和得率两方面对水飞蓟蛋白提取参数进行了优化。此外,对从水飞蓟籽中分离的蛋白质进行了表征。确定了从牛奶蓟种子中获得最高蛋白质（MTP）纯度的最佳条件为提取pH9.47，温度30°C，和提取时间180分钟。相反，在提取pH12，温度50°C，确定总蛋白质产量（MTY）的最佳值，提取时间167min。在这两组条件（MTP和MTY）下获得的蛋白质表现出相当的吸油能力（OAC），发泡,和乳化能力，以及稳定性，与以前关于种子蛋白的研究结果一致。两种蛋白质在pH11时具有最高的蛋白质溶解度。两种蛋白质的ζ电位在pH4时最接近零，表明它们接近等电点。MTP和MTY的抗氧化能力比其他蛋白分离物/浓缩物差。MTP和MTY含有高β折叠浓度,其可能增强热稳定性并降低蛋白质的消化率。总之,蛋白质提取过程显示出很高的潜力，可以实现大量的产量和显着的纯度，具有一些体面的技术和功能特性，从而为不同领域的各种应用带来了希望。
