Saavedra Isusi Gabriela Itziar, Marburger Johannes, Lohner Nils, van der Schaaf Ulrike S
Thermo Fisher Scientific, Pfannkuchstr. 10-12, D-76185 Karlsruhe, Germany.
Institute of Process Engineering in Life Sciences-Food Process Engineering, Karlsruhe Institute of Technology, Gotthard-Franz-Str. 3, D-76131 Karlsruhe, Germany.
Gels. 2023 Jun 8;9(6):473. doi: 10.3390/gels9060473.
Soy-based yoghurt alternatives were highly requested by consumers over the last few years. However, their texture does not always fulfil consumers' demands as such yoghurt alternatives are often perceived as too firm or too soft, sandy, or fibrous. In order to improve the texture, fibres, for example, in the form of microgel particles (MGP), can be added to the soy matrix. MGP are expected to interact with soy proteins, creating different microstructures and, thus, different gel properties after fermentation. In this study, pectin-based MGP were added in different sizes and concentrations, and the soy gel properties after fermentation were characterised. It was found that the addition of 1 wt.% MGP influenced neither the flow behaviour nor the tribological/lubrication properties of the soy matrix, regardless of the MGP size. However, at higher MGP concentrations (3 and 5 wt.%), the viscosity and yield stress were reduced, the gel strength and cross-linking density decreased, and the water-holding capacity was reduced. At 5 wt.%, strong and visible phase separation occurred. Thus, it can be concluded that apple pectin-based MGP serve as inactive fillers in fermented soy protein matrices. They can, therefore, be used to weaken the gel matrix purposely to create novel microstructures.
在过去几年中，消费者对基于大豆的酸奶替代品有很高的需求。然而，它们的质地并不总是能满足消费者的需求，因为这类酸奶替代品通常被认为太硬或太软、有沙质感或纤维感。为了改善质地，可以将例如微凝胶颗粒（MGP）形式的纤维添加到大豆基质中。预计MGP会与大豆蛋白相互作用，在发酵后产生不同的微观结构，从而具有不同的凝胶特性。在本研究中，添加了不同尺寸和浓度的基于果胶的MGP，并对发酵后的大豆凝胶特性进行了表征。结果发现，添加1 wt.%的MGP对大豆基质的流动行为和摩擦学/润滑特性均无影响，无论MGP的尺寸如何。然而，在较高的MGP浓度（3 wt.%和5 wt.%）下，粘度和屈服应力降低，凝胶强度和交联密度下降，持水能力降低。在5 wt.%时，出现了强烈且明显的相分离。因此，可以得出结论，基于苹果果胶的MGP在发酵大豆蛋白基质中充当惰性填料。因此，它们可用于有意削弱凝胶基质以创造新的微观结构。
