Institute of Agrochemistry and Food Technology (IATA, CSIC), C/Agustín Escardino 7, 46890 Paterna (Valencia), Spain.
Universidad de Santiago de Chile, Santiago, Chile.
Food Res Int. 2020 Oct;136:109300. doi: 10.1016/j.foodres.2020.109300. Epub 2020 May 8.
The aim of this study was to understand the contribution of hydrocolloids to oral structure breakdown of starch-based systems in relation to mouthfeel sensations. For this, carrot purees were prepared using corn starch and a different second thickener (λ-carrageenan, carboxymethylcellulose (CMC), xanthan gum, or an extra amount of starch). The viscosity decay of purees under in vitro oral conditions was measured (starch pasting cell adapted to a rheometer) when shearing at a constant shear rate in the presence of artificial saliva. Sensory properties of purees were described using the Flash Profile technique by a group of 13 panellists. Oral viscosity decay of systems was modelled using a second order structural kinetic equation that included three parameters: initial viscosity, rate of breakdown, and viscosity at equilibrium. Although they had the same initial viscosity, the structural breakdown of the purees in oral conditions varied, depending on the second thickener used. The structure of purees containing xanthan and λ-carrageenan were more resistant under oral conditions exhibiting a slow and smaller breakdown. In contrast, purees containing only starch showed a rapid and large decay because of the complete structure breakdown by amylase. For puree containing CMC, there was also a rapid decrease, but smaller than starch, indicating that part of the structure remained after digestion. Texture sensations freely described by assessors varied according to two main sensory dimensions, that were clearly related to the structural breakdown parameters. As expected, the dimension of thickness (from watery and liquid to thick and viscous) separated base purees from thickened purees and was related to the initial viscosity. The smoothness dimension (from rough and lumpy to the smooth and creamy) was related to the viscosity at equilibrium indicating that after the oral digestion, the characteristics of the remaining structure can explain differences in complex attributes of semisolid systems such as smoothness and creaminess.
本研究旨在了解水胶体对淀粉基体系口腔结构破坏的贡献及其与口感的关系。为此，使用玉米淀粉和不同的第二种增稠剂（λ-卡拉胶、羧甲基纤维素（CMC）、黄原胶或额外的淀粉）制备胡萝卜泥。在存在人工唾液的情况下，以恒定剪切率在体外口腔条件下测量泥的粘度衰减（适应流变仪的淀粉糊化单元）。使用 Flash Profile 技术由一组 13 名品评员描述泥的感官特性。使用包含三个参数的二阶结构动力学方程对系统的口腔粘度衰减进行建模：初始粘度、分解速率和平衡粘度。尽管它们具有相同的初始粘度，但在口腔条件下，纯泥的结构分解因所用的第二种增稠剂而不同。含有黄原胶和 λ-卡拉胶的泥在口腔条件下具有更高的结构稳定性，表现出缓慢而较小的分解。相比之下，仅含有淀粉的泥由于淀粉酶的完全结构分解而迅速且大量分解。对于含有 CMC 的泥，也有快速下降，但小于淀粉，表明消化后部分结构仍然存在。评估员自由描述的质地感觉根据两个主要感官维度而变化，这两个维度与结构分解参数明显相关。正如预期的那样，厚度维度（从水样和液体到浓稠和粘稠）将基础泥与增稠泥分开，与初始粘度相关。光滑度维度（从粗糙和块状到光滑和奶油状）与平衡粘度相关，表明在口腔消化后，剩余结构的特性可以解释半固态体系如光滑度和奶油感等复杂属性的差异。
