Herrero Ana M, Ruiz-Capillas Claudia
Institute of Food Science, Technology and Nutrition (ICTAN-CSIC), José Antonio Novais 10, 28040 Madrid, Spain.
Gels. 2021 Apr 20;7(2):48. doi: 10.3390/gels7020048.
Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable ( > 0.05) syneresis was observed in either sample. The pH values were similar ( > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher ( < 0.05) α-helix and lower ( < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.
近年来，由于乳液凝胶（EGs）在食品中的有趣应用，受到了相当多的关注。这项工作的目的是阐明奇亚籽油在由大豆分离蛋白（SPI）和藻酸盐制成的EGs的技术和结构特性中所起的作用。研究了两个体系：无油SPI凝胶（SPI/G）和含有奇亚籽油的相应SPI EGs（SPI/EG）。测定了SPI/G和SPI/EG的近似组成、技术特性（脱水收缩、pH值、颜色和质地）以及使用拉曼光谱的结构特性。在两个样品中均未观察到明显的（>0.05）脱水收缩。SPI/G和SPI/EG的pH值相似（>0.05），但它们的质地和颜色因奇亚籽油的存在而有显著差异。SPI/EG的发红程度显著较低，明度和黄度更高，并且比SPI/G表现出更大的穿刺强度和凝胶强度。拉曼光谱显示，在加入奇亚籽油形成相应的SPI/EG后，蛋白质二级结构发生了显著变化，即α-螺旋含量增加（<0.05），β-折叠、转角和无规结构含量降低（<0.05）。显然，这些结构变化与观察到的质地改变之间存在相关性。
