School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, West Midlands B15 2TT, United Kingdom; Department of Chemical Engineering and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia.
National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, United Kingdom.
Food Res Int. 2022 Dec;162(Pt B):112064. doi: 10.1016/j.foodres.2022.112064. Epub 2022 Oct 20.
Consumers are increasingly looking for new plant-based alternatives to substitute animal proteins in their diets but for some applications it can be difficult to achieve the desired product microstructure using only plant proteins. One approach to facilitate structuring is to mix these plant-based ingredients with a polysaccharide. Here, the phase behaviour and microstructure of quinoa protein isolate (QPI) in mixture with maltodextrin (MD) of two dextrose equivalents (DE 7 and 2) were investigated. The binodals of both QPI-MD phase diagrams showed an atypical shape, where the concentration of MD in the QPI-rich phase and of QPI in the MD-rich phase increased with overall biopolymer concentration. Molecular weight distribution and microstructure analyses revealed that both maltodextrins fractionated between the phases and were probably entrapped within the volume-spanning protein network in the QPI-rich phase, indicating a depletion flocculation mechanism of phase separation. The pre-heating of QPI and the removal of salt from the systems resulted in similarly atypical phase diagrams. The approach presented contributes to our understanding of the phase behaviour of mixtures between plant proteins and polysaccharides, while the results suggest that the formulation of plant-based products of predictable properties may be more challenging than anticipated.
消费者越来越多地寻找新的植物性替代品来替代饮食中的动物蛋白，但对于某些应用，仅使用植物蛋白很难实现所需的产品微观结构。一种促进结构形成的方法是将这些植物性成分与多糖混合。在这里，研究了藜麦蛋白分离物（QPI）与两种葡萄糖当量（DE7 和 2）的麦芽糊精（MD）混合物的相行为和微观结构。两种 QPI-MD 相图的双节点都呈现出非典型的形状，其中 QPI 丰富相中的 MD 浓度和 MD 丰富相中的 QPI 浓度随着总生物聚合物浓度的增加而增加。分子量分布和微观结构分析表明，两种麦芽糊精都在相之间分馏，并且可能被困在 QPI 丰富相中的体积跨越蛋白质网络中，表明相分离的耗尽絮凝机制。QPI 的预加热和系统中盐的去除导致类似的非典型相图。所提出的方法有助于我们理解植物蛋白和多糖之间混合物的相行为，同时结果表明，具有可预测性质的植物性产品的配方可能比预期的更具挑战性。
