Department of Food Science & Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
Key Laboratory of Meat Processing of Sichuan, Chengdu University, Chengdu 610106, People's Republic of China.
Food Res Int. 2023 Jan;163:112134. doi: 10.1016/j.foodres.2022.112134. Epub 2022 Nov 17.
This study aimed to investigate the rheological and textural properties of heat-induced gels from twelve legume protein isolates at pH 3.0 and 7.0, including black kidney bean (BKPI), speckled kidney bean (SKPI), panda bean (PDPI), cowpea (CPPI), mung bean (MPI), adzuki bean (API), rice bean (RPI), black soybean (BPI), soybean (SPI), chickpea (CPI), broad bean (BRPI) and pea (PPI). SDS-PAGE revealed that 7S globulin was prominent protein in BKPI, SKPI, PDPI, CPPI, MPI, API and RPI, the main protein fraction of CPI was 11S globulin, and BPI, SPI, BRPI and PPI contained both 7S and 11S globulins as major components. Based on the gel's Power Law constant (K') and hardness, twelve legume proteins were divided into three categories with high, medium and low gel strength. BKPI, SKPI and PDPI with Phaseolin being the major protein fraction showed high gel strength regardless of pH. Electrostatic interactions, hydrophobic interactions and hydrogen bonds were the most important intermolecular forces in the formation of legume protein gel networks, of which gel strength at pH 3.0 and pH 7.0 was significantly affected by electrostatic interactions and hydrogen bonds, respectively. Moreover, gel strength was also remarkably negatively influenced by the non-network proteins. SEM observation indicated that the microstructure of gels at pH 7.0 was denser and more homogeneous than that at pH 3.0, leading to better water holding capacity. These findings would be of great importance for understanding the differences in legume protein gels, and also laid the scientific support for expanding applications of legume proteins in gel-based foods.
本研究旨在研究 12 种豆类蛋白分离物在 pH 3.0 和 7.0 下形成的热诱导凝胶的流变性和质构特性，包括黑肾豆（BKPI）、花斑肾豆（SKPI）、熊猫豆（PDPI）、豇豆（CPPI）、绿豆（MPI）、红小豆（API）、饭豆（RPI）、黑大豆（BPI）、大豆（SPI）、鹰嘴豆（CPI）、蚕豆（BRPI）和豌豆（PPI）。SDS-PAGE 显示，7S 球蛋白是 BKPI、SKPI、PDPI、CPPI、MPI、API 和 RPI 中的主要蛋白质，CPI 的主要蛋白质部分是 11S 球蛋白，BPI、SPI、BRPI 和 PPI 都含有 7S 和 11S 球蛋白作为主要成分。根据凝胶的幂律常数（K'）和硬度，12 种豆类蛋白质被分为高、中、低凝胶强度三类。无论 pH 值如何，以伴球蛋白为主要蛋白质的 BKPI、SKPI 和 PDPI 均表现出高凝胶强度。静电相互作用、疏水相互作用和氢键是形成豆类蛋白质凝胶网络的最重要的分子间力，其中凝胶在 pH 3.0 和 pH 7.0 下的强度分别受到静电相互作用和氢键的显著影响。此外，凝胶强度也受到非网络蛋白质的显著负面影响。SEM 观察表明，pH 7.0 下凝胶的微观结构比 pH 3.0 下更致密、更均匀，导致更好的持水能力。这些发现对于理解豆类蛋白质凝胶的差异具有重要意义，也为扩大豆类蛋白质在凝胶基食品中的应用提供了科学支持。
