Yücetepe Aysun, Yavuz-Düzgün Merve, Şensu Eda, Bildik Fatih, Demircan Evren, Özçelik Beraat
Department of Food Engineering, Faculty of Engineering, Aksaray University, 68100 Aksaray, Turkey.
Department of Food Engineering, Faculty of Chemical and Metallurgical Engineering, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey.
J Food Sci Technol. 2021 Apr;58(4):1274-1285. doi: 10.1007/s13197-020-04636-7. Epub 2020 Jul 31.
is one of the most significant multicellular blue-green microalgae with a high protein content. The complex coacervation as an encapsulation technique allows the formation of proteins with improved functional properties and thermal stability. In this study, the effects of pH and protein concentrate (SPPC)-chitosan ratio on complex coacervation formation were examined in terms of ζ-potential, turbidity, visual observation and microscopic images. Based on the results, the strongest interaction between SPPC and chitosan occurred at pH of 5.5 and SPPC-chitosan ratio of 7.5:1 with a precipitation in the test tubes. Stable dispersions were obtained at a pH range of 2-4 for the SPPC-chitosan ratio of 7.5:1 inhibiting the precipitation which occurs at individual SPPC solutions at this pH range. Characteristic organic groups in the individual SPPC and chitosan solutions as well as the SPPC-chitosan coacervate formed at the optimal conditions were identified by using Fourier Transform Infrared (FT-IR) spectroscopy technique. Furthermore, thermal stability of the individual SPPC and chitosan solutions and the SPPC-chitosan coacervates were investigated using differential scanning calorimetry (DSC). The glass transition temperature and enthalpy were 209.5 °C and - 3.414 W/g for the complex coacervates and 180.5 °C and - 0.877 W/g for SPPC. It means that complex coacervation provided more thermally-stable SPPC in chitosan-SPPC coacervate than that of the individual SPPC. Our results might have important implications for the utilization of proteins especially for acidic beverage applications.
是最重要的多细胞蓝绿微藻之一，蛋白质含量高。复合凝聚作为一种包封技术，能够形成具有改善功能特性和热稳定性的蛋白质。在本研究中，从ζ电位、浊度、视觉观察和显微镜图像方面考察了pH值和大豆蛋白浓缩物（SPPC）与壳聚糖比例对复合凝聚形成的影响。结果表明，SPPC与壳聚糖之间的最强相互作用发生在pH值为5.5、SPPC与壳聚糖比例为7.5:1时，此时试管中有沉淀生成。对于SPPC与壳聚糖比例为7.5:1的体系，在pH值2 - 4范围内可获得稳定分散体，抑制了在此pH范围内单独SPPC溶液中发生的沉淀现象。利用傅里叶变换红外（FT - IR）光谱技术鉴定了单独的SPPC和壳聚糖溶液以及在最佳条件下形成的SPPC - 壳聚糖凝聚层中的特征有机基团。此外，使用差示扫描量热法（DSC）研究了单独的SPPC和壳聚糖溶液以及SPPC - 壳聚糖凝聚层的热稳定性。复合凝聚层的玻璃化转变温度和焓分别为209.5℃和 - 3.414W/g，SPPC的玻璃化转变温度和焓分别为180.5℃和 - 0.877W/g。这意味着复合凝聚在壳聚糖 - SPPC凝聚层中提供了比单独的SPPC更具热稳定性的SPPC。我们的结果可能对蛋白质的利用具有重要意义，特别是对于酸性饮料应用。
