Megusar Polona, Stopar David, Poklar Ulrih Natasa, Dogsa Iztok, Prislan Iztok
Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia.
Department of Microbiology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia.
Polymers (Basel). 2022 Aug 9;14(16):3242. doi: 10.3390/polym14163242.
Obtaining good-quality gluten-free products represents a technological challenge; thus, it is important to understand how and why the addition of hydrocolloids influences the properties of starch-based products. To obtain insight into the physicochemical changes imparted by hydrocolloids on gluten-free dough, we prepared several suspensions with different corn starch/potato starch/hydroxpropyl methyl cellulose/xanthan gum/water ratios. Properties of the prepared samples were determined by differential scanning calorimetry and rheometry. Samples with different corn/potato starch ratios exhibited different thermal properties. Xanthan gum and HPMC (hydroxypropyl methyl cellulose) exhibited a strong influence on the rheological properties of the mixtures since they increased the viscosity and elasticity. HPMC and xanthan gum increased the temperature of starch gelatinization, as well as they increased the viscoelasticity of the starch model system. Although the two hydrocolloids affected the properties of starch mixtures in the same direction, the magnitude of their effects was different. Our results indicate that water availability, which plays a crucial role in the starch gelatinization process, could be modified by adding hydrocolloids such as, hydroxypropyl methyl cellulose and xanthan gum. By adding comparatively small amounts of the studied hydrocolloids to starch, one can achieve similar thermo-mechanical effects by the addition of gluten. Understanding these effects of hydrocolloids could contribute to the development of better quality gluten-free bread with optimized ingredient content.
获得高质量的无麸质产品是一项技术挑战；因此，了解添加水胶体如何以及为何会影响淀粉基产品的特性非常重要。为了深入了解水胶体对无麸质面团造成的物理化学变化，我们制备了几种具有不同玉米淀粉/马铃薯淀粉/羟丙基甲基纤维素/黄原胶/水比例的悬浮液。通过差示扫描量热法和流变学测定所制备样品的特性。具有不同玉米/马铃薯淀粉比例的样品表现出不同的热性能。黄原胶和羟丙基甲基纤维素（HPMC）对混合物的流变特性有很大影响，因为它们增加了粘度和弹性。羟丙基甲基纤维素和黄原胶提高了淀粉糊化温度，同时也增加了淀粉模型体系的粘弹性。尽管这两种水胶体对淀粉混合物特性的影响方向相同，但影响程度不同。我们的结果表明，在淀粉糊化过程中起关键作用的水分有效性可以通过添加羟丙基甲基纤维素和黄原胶等水胶体来改变。通过向淀粉中添加相对少量的所研究水胶体，可以实现与添加麸质类似的热机械效果。了解水胶体的这些作用有助于开发出成分优化、质量更好的无麸质面包。
