Masticatory performance of denture wearers was compared with that of the normal subjects by analyzing the behavior of the mechanical properties of the bolus. The index of the ability to comminute bolus was described as the total number of masticatory strokes until swallowing and therefore this was chosen as the first index. Principal Component Analysis (PCA) on the data of six parameters; 80% energy, elasticity, viscosity, hardness, adhesiveness, and cohesiveness, indicated that the cohesiveness was independent of the other parameters and should be evaluated as the second index of the ability to dilute bolus with saliva. Two factor scores of the other parameters were calculated using the standardized scoring coefficient obtained from PCA and factor analysis on the data of the normal subjects, which realized to compare two groups on the same plane of factor scores. The movement of factor scores on the factor plane would indicate the total behavior of mechanical properties of bolus and was chosen as the third index of the ability to knead bolus. Triangle Diagram (TD) was completed by using these three indices. On the TD, all the subjects were lower level at least in one index than the normal subjects in all the foods.

http://lib.tmd.ac.jp/jmd/55034/02_yoshimine.pdf

Analysis of the mechanical properties of food bolus masticated by denture wearers

Influence of the viscoelastic properties of rice dough on the mechanical properties and the microstructure of rice crackers was experimentally investigated to predict and control the quality of the rice cracker in the early stage of the lengthy manufacturing process. Various rice doughs steamed for 5, 30, or 60 min and kneaded for 5, 10, or 15 min were examined. Longer steaming and kneading resulted in lower G' and G″ and higher tan δ, specific volume of the rice crackers, decreased nonuniform and deficient network, and thinner cell wall in rice cracker sections. There was a high correlation between tan δ of rice dough and specific volume of the rice cracker samples (R2  > 0.79). The hardness of the rice crackers increased with extending the kneading time for 5 and 30 min as the tan δ increased, while those of the rice crackers made from the rice doughs steamed for 60 min decreased inversely. These results indicated that qualities of rice crackers can be predicted and quantified by measuring viscoelasticity of actual rice doughs during the process. PRACTICAL APPLICATIONS: Improved methods to control quality of end product in manufacturing process and to develop new products with unique textures are desired. We established the new method to quantify the rice dough and this method has already been used for confirming equivalency or improvement of rice dough during manufacture of rice crackers when instrument or condition have changed.

Effects of rheological properties of rice dough during manufacture of rice cracker on the quality of the end product

https://www.jstage.jst.go.jp/article/soshaku1991/16/2/16_2_70/_pdf

Akira Itou

Papers

Development of Rice Cracker for Aged People