Ruzengwe Faith Matiza, Amonsou Eric O, Kudanga Tukayi
Department of Biotechnology and Food Technology, Durban University of Technology, P.O. BOX 1334, Durban 4000, South Africa.
Department of Biotechnology and Food Technology, Durban University of Technology, P.O. BOX 1334, Durban 4000, South Africa.
Food Res Int. 2020 Nov;137:109734. doi: 10.1016/j.foodres.2020.109734. Epub 2020 Sep 22.
Interest in plant protein-based hydrogels with desirable strength has been increasing in recent years. In this study, Bambara groundnut protein isolate (BPI) was crosslinked with transglutaminase (TGase) (0 - 25 U/g protein) during gelation and rheological, textural and microstructural properties of the resulting hydrogels were investigated. Treatment with TGase up to 15 U/g protein resulted in the formation of hydrogels with small pores and an organised homogeneous network. G' of TGase-treated BPI hydrogels was more than ten-fold higher than G" throughout the frequency range of 0-100 rad/s, suggesting dominance of the elastic like behaviour. BPI hydrogel with the highest G' (6967 Pa) and hardness (5.60 N) was formed at 15 U/g protein of TGase activity. The hydrogel had a high distribution β-sheets (53.52%) and α-helixes (26.17%) as compared to the β-turns and random coils. However, a further increase in TGase activity did not improve the hydrogel properties. Transglutaminase mediated crosslinking of BPI hydrogel was demonstrated by the reduction in amine and thiol groups and the formation of a new protein band (56 kDa) in crosslinked hydrogels. Overall, TGase promoted the formation of a strong gel with an organised network.
近年来，人们对具有理想强度的植物蛋白基水凝胶的兴趣日益增加。在本研究中，在凝胶化过程中，将 Bambara 花生分离蛋白（BPI）与转谷氨酰胺酶（TGase）（0 - 25 U/g 蛋白）交联，并研究所得水凝胶的流变学、质地和微观结构特性。用高达 15 U/g 蛋白的 TGase 处理导致形成具有小孔和有组织的均匀网络的水凝胶。在 0 - 100 rad/s 的整个频率范围内，TGase 处理的 BPI 水凝胶的 G' 比 G" 高十多倍，表明弹性行为占主导。在 TGase 活性为 15 U/g 蛋白时形成了具有最高 G'（6967 Pa）和硬度（5.60 N）的 BPI 水凝胶。与 β-转角和无规卷曲相比，该水凝胶具有高比例的 β-折叠（53.52%）和 α-螺旋（26.17%）。然而，TGase 活性的进一步增加并没有改善水凝胶的性能。通过交联水凝胶中胺基和巯基的减少以及新蛋白条带（56 kDa）的形成，证明了转谷氨酰胺酶介导的 BPI 水凝胶交联。总体而言，TGase 促进了具有有组织网络的强凝胶的形成。
