Programa de Posgrado en Alimentos del Centro de la República (PROPAC), Research and Graduate Studies in Food Science, School of Chemistry, Universidad Autónoma de Querétaro, 76010 Santiago de Querétaro, Querétaro, Mexico.
Programa de Posgrado en Alimentos del Centro de la República (PROPAC), Research and Graduate Studies in Food Science, School of Chemistry, Universidad Autónoma de Querétaro, 76010 Santiago de Querétaro, Querétaro, Mexico.
Int J Biol Macromol. 2021 Jan 1;166:861-868. doi: 10.1016/j.ijbiomac.2020.10.242. Epub 2020 Nov 3.
Vegetables are considered to be a sustainable source of promising biomaterials such as proteins and polysaccharides. In this study, four protein isolates (amaranth protein isolate API, amaranth globulin-rich protein isolate AGR, bean protein isolate BPI, and bean phaseolin-rich protein isolate BPR) were structurally characterized under different pH conditions (2-12) and their compatibility behavior with xanthan gum (XG) in aqueous medium was described. All protein isolates showed β turn and β sheet (78.24-81.11%), as the major secondary structures without statistically significant difference under the pH conditions surveyed. Protein isolates show solubility at pH ≤ 3 (40.4-85.1%) and pH ≥ 8 (57.6-99.9%) and surface hydrophobicity results suggest protein denaturation at pH ≤ 3. In the compatibility study, API/XG ratios between 1:1 and 5:1 at pH from 7 to 9 and the BPI/XG ratios from 1:1 to 20:1 at pH 7 form gels that do not require heating nor crosslinking agent addition. Zeta potential results, on the other hand, evidenced that formation of gels is driven by attractive electrostatic interaction of the charged regions of both biopolymers and intermolecular interactions such as hydrogen bonds.
蔬菜被认为是有前途的生物材料（如蛋白质和多糖）的可持续来源。在本研究中，四种蛋白质分离物（苋菜籽蛋白分离物 API、苋菜籽球蛋白丰富的蛋白分离物 AGR、大豆蛋白分离物 BPI 和大豆伴球蛋白丰富的蛋白分离物 BPR）在不同 pH 值条件（2-12）下进行了结构表征，并描述了它们在水介质中的与黄原胶（XG）的相容性行为。所有蛋白质分离物在调查的 pH 值条件下均显示β转角和β片层（78.24-81.11%）作为主要二级结构，没有统计学上的显著差异。蛋白质分离物在 pH≤3（40.4-85.1%）和 pH≥8（57.6-99.9%）时具有溶解性，表面疏水性结果表明 pH≤3 时蛋白质变性。在相容性研究中，在 pH 值为 7 至 9 时，API/XG 比例为 1:1 至 5:1，BPI/XG 比例为 1:1 至 20:1 形成凝胶，不需要加热或添加交联剂。另一方面，Zeta 电位结果表明，凝胶的形成是由两种生物聚合物带电区域之间的吸引力静电相互作用以及氢键等分子间相互作用驱动的。
