RHEOLOGICAL PROPERTIES AND OILINESS OF MONODISPERSED EMULSION GEL

通过力学分析和感官评价研究了油滴在琼脂基质中的作用。在凝胶制备的连续阶段，证实了平均液滴直径分别为1.5、3.3、6.5和12.2 μ m的单分散o/w乳液的稳定性和均匀性。通过力学分析，研究了油滴在琼脂凝胶基质中在大变形和小变形条件下的作用。在大变形条件下，通过压缩试验和穿刺试验考察了油滴对凝胶强度的影响。乳液凝胶的抗压强度随油滴尺寸和油体积分数的增加而降低，而穿刺强度不随油滴尺寸的增加而变化。在小变形试验中，对乳液凝胶的蠕变行为和动态维弹性性能进行了评价。随着油滴尺寸的增大，乳液凝胶小变形试验的测定值基本保持不变。因此，为了证明油滴对乳液凝胶的影响，大变形下的压缩测量有助于区分油滴大小对乳液凝胶流变性能的影响。采用配对对比法对平均油滴直径分别为1.5、6.5和12.2 μ m的乳液凝胶进行感官评价。评估小组由18名实验室学生组成。感官评价结果表明，含小油滴的试样比含大油滴的试样硬度大。油滴大的样品比油滴小的样品更油。

Effects oil droplets in an agar gel matrix were investigated by mechanical analysis and sensory evaluation. The stability and uniformity of monodispersed o/w emulsion with mean droplet diameter of 1.5, 3.3, 6.5 and 12.2 mum were confirmed during successive stages of gel preparation. Effects of oil droplets in an agar gel matrix were investigated by mechanical analysis under large and small-deformations. Under large deformation, the effects of oil droplets on gel strength were examined by compressive and puncture test. Thc compressive strength of the emulsion gels decreased with both increases in oil droplet size and oil volume fraction, while the puncture strength of the emulsion gel did not change with an increase in oil droplet size. For small-deformation test, creep behaviors and dynamic vicoelastic properties of emulsion gels were evaluated. Both the determined values by small-deformation test for the emulsion gels were almost constant for increasing oil droplet size. Thus, to demonstrate effects of oil droplets on emulsion gel, compression measurements under large-deformation arc useful to discriminate the oil droplet size on the rheological properties of emulsion gel.Sensory evaluation for emulsion gels containing the oil droplets with mean droplet diameter of 1.5, 6.5 and 12.2 mum was performed by the paired comparison method. The evaluation panels were coin posed of 18 laboratory students. Results of sensory evaluation showed that the sample containing small oil droplets was harder than that with large oil droplets. And the large oil droplets sample was oilier than that with small oil droplets.