Xia Xiaoyu, Zhang Binyang, Huang Yuyang, Zhu Ying, Qu Min, Liu Linlin, Sun Bingyu, Zhu Xiuqing
College of Food Engineering, Harbin University of Commerce, Harbin 150028, China.
Foods. 2024 Jul 2;13(13):2117. doi: 10.3390/foods13132117.
Freezing affects texture and induces the loss of gel quality. This study investigated the effects of methylcellulose (MC) (0.2%, 0.4%, 0.6%) and sodium hexametaphosphate (SHMP) (0.15%, 0.3%) on the gel textural and structural properties of SPI gels before and after freezing, and explores the synergistic enhancement of gel texture and the underlying mechanisms resulting from the simultaneous addition of SHMP and MC to SPI gels. It was revealed that MC improved the strength of SPI gels through its thickening properties, but it could not inhibit the reduction of SPI gels after freezing. The 0.4% MC-SPI gel exhibited the best gel strength (193.2 ± 2.4 g). SHMP inhibited gel reduction during freezing through hydrogen bonding and ionic interactions; it enhanced the freezing stability of SPI gels. The addition of 0.15% SHMP made the water-holding capacity in SPI gels reach the highest score after freezing (58.2 ± 0.32%). The synergistic effect of MC and SHMP could improve the strength and the freezing stability of SPI gels. MC facilitated the release of ionizable groups within SPI, causing negatively charged SHMP groups to aggregate on the SPI and inhibit the freezing aggregation of proteins. These results provide a strong basis for the improvement of cryogenic soy protein gel performance by SHMP and MC.
冷冻会影响质地并导致凝胶品质下降。本研究考察了甲基纤维素（MC）（0.2%、0.4%、0.6%）和六偏磷酸钠（SHMP）（0.15%、0.3%）对大豆分离蛋白（SPI）凝胶在冷冻前后的凝胶质地和结构性质的影响，并探究了同时向SPI凝胶中添加SHMP和MC对凝胶质地的协同增强作用及其潜在机制。结果表明，MC通过其增稠特性提高了SPI凝胶的强度，但它不能抑制冷冻后SPI凝胶强度的降低。0.4%MC-SPI凝胶表现出最佳的凝胶强度（193.2±2.4g）。SHMP通过氢键和离子相互作用抑制冷冻过程中的凝胶强度降低；它提高了SPI凝胶的冷冻稳定性。添加0.15%SHMP使SPI凝胶在冷冻后的持水能力达到最高值（58.2±0.32%）。MC和SHMP的协同作用可以提高SPI凝胶的强度和冷冻稳定性。MC促进了SPI中可电离基团的释放，使带负电荷的SHMP基团聚集在SPI上并抑制蛋白质的冷冻聚集。这些结果为通过SHMP和MC改善低温大豆蛋白凝胶性能提供了有力依据。
