School of Applied Sciences, RMIT University, City Campus, Melbourne, Vic 3001, Australia.
Food Chem. 2012 Dec 1;135(3):1455-62. doi: 10.1016/j.foodchem.2012.06.014. Epub 2012 Jun 16.
Co-solute requirements for high methoxy pectin gelation were observed by the addition of glucose syrup and polydextrose at concentrations varying from 50% to 78% (w/w). Pectin content was fixed at 2% (w/w) in formulations. Studies from small deformation dynamic oscillation in shear, modulated differential scanning calorimetry and environmental scanning electron microscopy are reported. Structural properties of pectin preparations were recorded in relation to the molecular weight and concentration of added co-solute in an acidic environment (pH ∼3.0). High levels of co-solute induce formation of weak pectin gels at elevated temperatures (even at 95°C), which upon subsequent cooling exhibit increasing strength and convert to a clear glass at subzero temperatures. Fourier Transform Infrared Spectroscopy and wide angle X-ray diffraction were practised to examine the nature of interactions between polymer and co-solute and the extent of amorphicity of preparations. Glucose syrup is an efficient plasticiser leading to a reduction in the glass transition temperature (T(g)) of the pectin network, whereas polydextrose assists in the formation of stronger pectin gels in the rubbery state.
共溶剂对高甲氧基果胶凝胶化的要求通过添加浓度为 50%至 78%（w/w）的葡萄糖浆和聚右旋糖来观察。果胶含量在配方中固定为 2%（w/w）。报道了来自小变形动态振荡剪切、调制差示扫描量热法和环境扫描电子显微镜的研究。在酸性环境（pH ∼3.0）下，记录了果胶制剂的结构特性与添加共溶剂的分子量和浓度的关系。在较高温度（甚至 95°C）下，高浓度的共溶剂会诱导形成弱果胶凝胶，随后冷却时会逐渐增强，并在零下温度下转变为透明玻璃。傅里叶变换红外光谱和广角 X 射线衍射用于研究聚合物和共溶剂之间相互作用的性质以及制剂的非晶度程度。葡萄糖浆是一种有效的增塑剂，导致果胶网络的玻璃化转变温度（T(g)）降低，而聚右旋糖有助于在橡胶态下形成更强的果胶凝胶。
