Research on food rheology in the mouth by mastication measurement.

1.当受试者吃各种质地的食物时，测量第一磨牙的力和运动。力-位移曲线的食物在口中获得的第一口的食物，并与曲线测量的机器进行比较。各种食物的第一次咬合时的最大力为200 N，而机器获得的最大咬合力为2500 N。食物的最大力量较小的同意与那些请老年人。在食用浓度为0.05%至0.5%的结冷胶时，用嵌入人造树脂腭中的六个压力传感器测量腭压。当受试者被要求自然地吃凝胶时，他们通过用舌头按压在低于30 kPa的断裂应力下吃凝胶，并且通过用牙齿咬在其之上吃凝胶。由于结冷胶凝胶的动态粘弹性模量G'和G”在低于0.5%的含量下变化超过两个数量级而没有频率依赖性，结冷胶可以用作天然增稠剂。使用超声脉冲多普勒频移测量吞咽的0至0.5%的结冷胶溶胶和凝胶通过会厌正上方的咽的流速。不同结冷胶含量和水的溶胶和凝胶的平均流速被发现是0.1米/秒几乎与结冷胶含量无关。相比之下，尽管凝胶的最大流速的平均值在高于0.1%时为0.2m/s，但对于低于0.1%的较低结冷胶含量，其增加，并且对于纯水达到0.5m/s，显示出咽中水的速度的宽分布。

1. Forces and movements of the first molar were measured while a subject was eating various textural foods. Force-displacement curves of foods in the mouth were obtained for the first bite of the food and compared with curves measured by a machine. The maximum force at the first bite for various foods was 200 N in contrast to 2500 N obtained by the machine. Foods with the smaller maximum force agreed with those that please to elderly people.2. Palatal pressure while eating gellan gel of concentration 0.05 to 0.5 % was measured with six pressure transducers embedded in an artificial resin palate. When subjects were asked to eat the gel naturally, they ate the gel with a break stress below 30 kPa by pressing with the tongue and above it by biting with the teeth. Since dynamic viscoelastic moduli G' and G" of gellan gel changed by more than two orders of magnitude without frequency dependence below 0.5 % content, gellan may be of use as a natural agent for thickening.3. An ultrasonic pulsed Doppler shift was used to measure the flow velocity of swallowed gellan sol and gel of 0 to 0.5 % through the pharynx just above the epiglottis. The average flow velocity of sol and gel with different gellan content and water was found to be 0.1 m/s almost independent of gellan content. By contrast, although the average of the maximum flow velocity of the gel was 0.2 m/s above 0.1 %, it increased for lower gellan content below 0.1 % and reached 0.5 m/s for pure water, showing a wide distribution of the velocity of water in the pharynx.