Saavedra Isusi Gabriela Itziar, Paz Puga Domenica, van der Schaaf Ulrike Sabine
Chair of Food Process Engineering, Institute of Process Engineering in Life Sciences, Karlsruhe Institute of Technology, Gotthard-Franz-Str. 3, Building No. 50.31, D-76131 Karlsruhe, Germany.
Foods. 2022 Jan 22;11(3):294. doi: 10.3390/foods11030294.
Soy-based yoghurt alternatives are nowadays preferred by consumers. However, they are often perceived as too firm or too soft, sandy, or fibrous. In order to improve this, fibres, especially as in form of microgel particles (MGP), and fats are added to the soy matrix to create a creamy mouthfeel. Both fat and pectin-based MGP can interact with each other and with the protein matrix, creating different microstructures. This can influence the rheological and tribological properties of plant-based protein gels. This works focuses on the effect droplet stabilisation (coconut oil) on the rheological and tribological behaviour of the fermented stirred soy protein gels. For this, fat droplets were stabilised with MGP, SPI, or a mixture of both. Whilst the rheological behaviour remained unchanged for all investigated samples, the tribology of the samples depended on the emulsifier used. The addition of fat decreased the traction coefficient compared to the reference samples without fat. Even though all samples had the same fat content and identical droplet sizes, differences were observed in their lubricating properties. Droplets stabilised solely with SPI presented the best lubricating properties, as indicated by the lowest traction coefficient. Samples stabilised with MGP (or in mixture with SPI) caused higher friction.
如今，基于大豆的酸奶替代品受到消费者青睐。然而，它们常被认为质地过硬或过软、有沙质感或呈纤维状。为改善这一情况，会向大豆基质中添加纤维，尤其是微凝胶颗粒（MGP）形式的纤维以及脂肪，以营造出丝滑的口感。脂肪和基于果胶的MGP都能相互作用，并与蛋白质基质相互作用，形成不同的微观结构。这会影响植物基蛋白质凝胶的流变学和摩擦学特性。这项研究聚焦于液滴稳定化（椰子油）对发酵搅拌型大豆蛋白凝胶的流变学和摩擦学行为的影响。为此，用MGP、大豆分离蛋白（SPI）或两者的混合物来稳定脂肪滴。虽然所有研究样品的流变学行为保持不变，但样品的摩擦学特性取决于所使用的乳化剂。与不含脂肪的参比样品相比，添加脂肪降低了牵引系数。尽管所有样品的脂肪含量相同且液滴大小相同，但在其润滑性能方面仍观察到差异。仅用SPI稳定的液滴呈现出最佳的润滑性能，其牵引系数最低即表明了这一点。用MGP（或与SPI混合）稳定的样品产生的摩擦力更大。
