Department of Physics, Zhengzhou University of Light Industry, Zhengzhou, China.
Carbohydr Polym. 2013 Oct 15;98(1):744-9. doi: 10.1016/j.carbpol.2013.04.024. Epub 2013 Jun 6.
The feasibility of textural and rheological modification of gels containing κ-carrageenan (KC) and locust bean gum (LBG) by addition of konjac glucomannan (KGM) was investigated. Special attention was paid to the effect of polysaccharide degradation during heating at acidic pH. The general effect of polysaccharide degradation was to decrease the Young's modulus, while the fracture strain in extension was scarcely affected unless the degradation was very severe. Differential scanning calorimetry showed that the melting peak corresponding to dissociation of KC-KGM bonds decreased faster than the melting peak of KC-only bonds with increasing degree of polysaccharide degradation. The implication is that as degradation proceeds, fewer KGM molecules can interact with KC to form elastic bonds, and the excess of KGM which reinforces the existing elastic network and increases the fracture strain actually increases. For this reason, the fracture strain remains nearly unchanged with increasing degradation levels. A decrease in fracture strain is thus observed only at very severe degradations, where KC no longer forms a self-supporting gel by itself.
研究了通过添加魔芋葡甘聚糖（KGM）来改变含有κ-卡拉胶（KC）和刺槐豆胶（LBG）的凝胶的质地和流变性质的可行性。特别关注了在酸性 pH 值下加热时多糖降解的影响。多糖降解的一般影响是降低杨氏模量，而在拉伸时的断裂应变几乎不受影响，除非降解非常严重。差示扫描量热法表明，随着多糖降解程度的增加，对应 KC-KGM 键解离的熔融峰比仅 KC 键的熔融峰下降得更快。这意味着随着降解的进行，与 KC 形成弹性键的 KGM 分子减少，而增强现有弹性网络并增加断裂应变的多余 KGM 实际上增加。因此，随着降解程度的增加，断裂应变几乎保持不变。只有在非常严重的降解情况下，即 KC 不再自行形成自支撑凝胶时，才会观察到断裂应变的下降。
