Potato maltodextrin (Paselli Excel; DE < 3) was used at a fixed concentration of 15 wt %. On holding at 5°C after rapid quenching from 45°C the onset of conversion from disordered coils to aggregated double helices was seen as a steep increase in turbidity (monitored by absorbance at 600 nm) after ～50 min, and gelation was observed (visually) after ～120 min. Incorporation of increasing concentrations of gum arabic (1,2,4 and 8 wt %) caused a large, progressive decrease in the time required for structure formation and gelation to occur. A similar massive increase in rate of self-association of maltodextrin was observed for mixtures with the same concentrations (1, 2, 4 and 8 wt %) of hydroxypropylmethylcellulose (HPMC). Unlike gum arabic, however, HPMC caused very large increases in the values of turbidity recorded immediately after quenching. This cannot be attributed to phase separation, since the mixtures did not resolve into two liquid layers on high-speed centrifugation, or to ordering of maltodextrin, which was seen as a sharp increase in turbidity at longer times. Our interpretation is that segregative interactions with disordered maltodextrin promote hydrophobic association of HPMC at temperatures where it would normally remain un-associated, in the same way as HPMC and gum Arabic promote self-association of maltodextrin. These conclusions accord well with a previous investigation which showed massive precipitation of low-DE potato maltodextrin from single-phase mixtures with disordered gelatin.
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机译：用15wt％的固定浓度使用马铃薯麦芽糖糊精（Paselli Excel; de <3）。在从45°C快速淬火后保持5°C的转化率到聚集的双螺旋的转化率的开始被视为〜50分钟后浊度（通过600nm的吸光度监测）陡峭增加，观察到凝胶化（视觉上）〜120分钟后。在结构形成和凝胶化所需的时间内掺入增加阿拉伯（1,2,4和8wt％）的牙龈阿拉伯（1,2,4和8wt％）的浓度增加。对于具有相同浓度（1,2,4和8wt％）的羟丙基甲基纤维素（HPMC）的混合物，观察到麦芽糖糊精的自我关联率类似的大规模增加。然而，与阿拉伯语外，HPMC引起淬火后立即记录的浊度值的增加。这不能归因于相分离，因为混合物未在高速离心中分解成两个液体层，或者对麦芽糖糊精的排序进行排序，这被认为是在较长时间的浊度急剧增加。我们的解释是，与无序麦芽糖糊精的分离相互作用促进HPMC在通常保持未经关联的温度下的疏水性关联，与HPMC和胶阿拉伯语促进麦芽糖糊精的自我关联。这些结论与先前的调查相吻合，其显示出从具有无序明胶中的单相混合物的低De马铃薯麦芽糖糊精的大量沉淀。
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