Investigation of phase separation in mixed gels which are suitable for foods for person of advanced age.

这种凝胶是众所周知的适合老年人的食物之一，他们不能轻易吞咽。我们制备了琼脂/明胶和明胶/卡拉胶混合凝胶，其组成相同，但具有不同的相分离结构，并研究了它们的机械和感官性能。首先将混合物保持在高于明胶的胶凝温度的温度下并搅拌选定的时间，然后将其冷却至低于明胶的胶凝温度。两种混合凝胶的相分离结构根据混合温度而变化。明胶凝胶的应力-应变曲线服从BST表达式，混合凝胶的应力-应变曲线服从S型破裂表达式，混合凝胶的破裂应力和S型破裂表达式中的非线性参数可由应力-应变曲线计算得到。根据感官测试，当混合凝胶的非线性参数增加时，许多小组成员认为混合凝胶更加“有弹性”、“光滑”、“不弱”和“粘稠”。根据这些结果，建议将非线性参数作为食品质地光滑度的一个指标。

The gel is well-known as one of suitable foods for elderly people who could not swallow easily. We prepared agar/gelatin and gelatin/carrageenan mixed gels with the same composition but with a different phase-separation structure, and investigated their mechanical and sensory properties. The mixture was first kept at temperature above the gelling temperature of gelatin and stirred for the selected period, before cooling it below the gelling temperature of gelatin. The phase-separation structure of both mixed gels was varied depending on the mixing temperature. A stress-strain curve of the gelatin gel obeyed the BST expression, and that of every mixed gel obeyed the sigmoid rupture expression.The rupture stress and the nonlinear parameter in the sigmoid rupture expression on mixed gels could be calculated from the stress-strain curve. According to the sensory test, when the nonlinear parameter of mixed gels increased, many panelists recognized that the mixed gels were more "elastic", "smooth", "not weak", and "sticky". From these results, the nonlinear parameter was suggested to be an index for the smoothness of the food texture.