Mastication patterns

Fig. 1 shows, at low magnification, particles of Gouda cheese expectorated after 5 chews. Clearly in this short time span the first subject (top half) has saturated the sample more completely with saliva and caused more extensive melting of the fat, than the second subject (lower half). Such factors may greatly influence the subjects perceptions of the textural character of the cheese. From examination of mastication patterns it may be possible to determine which factors are influential in assessment of food texture. 

The foregoing mastication pattern is characteristic of the several fully formed thermoplastic polyurethane elastomer compositions we have examined. An obvious question the pattern raises is why mastication reduces already formed polymer to such essentially constant low viscosity level under a given set of shear/temperature/time conditions while the same conditions raise the viscosity of the same composition of forming polymer to a much higher and growing or constant viscosity level, (e.g., Polymer 5, Figure 3). 

When the printed pattern is applied to the ware above tlie glaze, the mordant receives a larger proportion of gum mastic but where enameling colors are used for the muffle, a sine is applied to the surface of the glaze, composed of spirits of turpentine, with a small portion of gum mastic dissolved in it sometimos rosin and sugar of load being added.. 

We can determine what features of the chewing sequence influence assessment of particular textural characteristics of food by using this approach to examine the interaction between food and consumer during the mastication process. We should then be able to develop mathematical models for perception of textural qualities which take into account different texture combinations (for example, assessment of hardness in both elastic and brittle foods), and different breakdown patterns. Although currently at an early stage, mastication analysis shows promise for enhancing our measurement of perceived texture in foods. 

The test foods studied here were five kinds of tomatoes. When eating food, humans first masticate the food with their teeth and then taste it. Therefore, we used a mixer in place of teeth and crushed tomatoes before measuring them. The preconditions were established by keeping the electrode immersed in standard juice, i.e., commercial canned tomato juice without NaCl added, for a long period of time. The origin of the output pattern was taken under these preconditions. Standard juice was used for the reference electrical potential pattern. The standard deviations between different lots of membrane were about 3mV. The same set of the eight membranes was used throughout the measurements for all tomatoes. 

Figure 12 shows an example of the characteristic pattern we encountered in this type of experiment in the mastication of a high quality (2.00) MDI/PTAd (MW 1000)/1.4-BD0 composition, Polymer 20, taken from the shelf. Granules of Polymer 20 were pre-dried (75°C/1 mm Hg/6 hours, then 25°C/1 mm Hg/over Drierite/ 20 hours) before mastication. 

From the earliest recorded times, man has utilized natural polymers. Such materials as asphalt, amber, and gum mastic are referred to in the written records of very early civilizations and, later, of the ancient Greeks and Romans. The pattern of use followed the classic human approach, namely, putting something to work without understanding its fundamental nature. Unfortunately, this failure to study delayed the effective utilization of synthetic polymers until the twentieth century. 

Mestres et al. used nose-space extraction to monitor the influence of whey protein gel texture on volatile release patterns during mastication [69,70]. The retronasal aroma release was followed and compared to sensory perception of overall aroma intensity, with the objective to And a connective link between physicochemical release patterns and perceived sensory impressions. Gel texture was foimd to be correlated with the in vivo physicochemical release patterns and to the corresponding retronasal aroma perception. 

The key mechanical tests defined in ANSI 136.1 involves tile-to-tile shear strength after dry conditioning and after water immersion. In this method, adhesive mastic is appHed to the unglazed back of a 108 mm x 108 mm test tile using a specified template to produce a pattern of equally spaced circles of adhesive on the back of the tile. 

---