Brenner Tom, Achayuthakan Piyada, Nishinari Katsuyoshi
Graduate School of Human Life Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan.
Biotechnology Program, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Dusit, Bangkok, 10300, Thailand.
J Texture Stud. 2013 Feb;44(1):66-74. doi: 10.1111/j.1745-4603.2012.00366.x. Epub 2012 Jul 31.
Small and large deformation tests were performed on polysaccharide-based gels containing konjac glucomannan, locust bean gum and κ-carrageenan. Low pH degradation of κ-carrageenan during heating led to lower gel strength. When κ-carrageenan degradation was avoided, the linear-regime rheology was dominated by the κ-carrageenan content, and the storage Young's modulus (E') was found to decrease with decreasing κ-carrageenan concentration. The large deformation behavior, however, was dominated by the konjac glucomannan concentration, and the rupture strain increased strongly with increasing konjac concentration. These two opposing trends led to a maximum in rupture stress in extension tests. No rupture was observed in compression of the gels at the polysaccharide concentrations tested. The compression force of konjac-rich gels was lower than that observed for gels without konjac at low-compression degrees, but it was similar to or higher at high-compression degrees, above 60-80%, indicating the higher degree of strain hardening of konjac-rich gels. PRACTICAL APPLICATIONS: Mixing of different polysaccharides has been used for widening the texture range, and it was shown in this report that the mixture of konjac glucomannan, locust bean gum and κ-carrageenan in the presence of sucrose and acid can produce jellies with various textures.
对含有魔芋葡甘聚糖、刺槐豆胶和κ-卡拉胶的多糖基凝胶进行了小变形和大变形测试。加热过程中κ-卡拉胶的低pH降解导致凝胶强度降低。当避免κ-卡拉胶降解时，线性区域流变学主要受κ-卡拉胶含量的影响，并且发现储能杨氏模量（E'）随着κ-卡拉胶浓度的降低而降低。然而，大变形行为主要受魔芋葡甘聚糖浓度的影响，并且断裂应变随着魔芋浓度的增加而强烈增加。这两种相反的趋势导致拉伸试验中的断裂应力出现最大值。在所测试的多糖浓度下，凝胶压缩时未观察到破裂。在低压缩程度下，富含魔芋的凝胶的压缩力低于不含魔芋的凝胶，但在高压缩程度（高于60-80%）下，它与不含魔芋的凝胶相似或更高，这表明富含魔芋的凝胶具有更高程度的应变硬化。实际应用：不同多糖的混合已被用于拓宽质地范围，并且本报告表明，在蔗糖和酸存在的情况下，魔芋葡甘聚糖、刺槐豆胶和κ-卡拉胶的混合物可以生产出具有各种质地的果冻。
