The difficulty in masticating and swallowing rice cake was quantified. Healthy subjects ate pieces of rice cake (9 g and 3 g) and a modified product (9 g). We used electromyography to measure the activity of the jaw-closing and -opening muscles during chewing, as well as the suprahyoid muscle activity, laryngeal movement, and sound during swallowing. The smaller the rice cake, the shorter the mastication time, the fewer the number of chews, and the less the jaw-closing muscle activity. A modified rice cake product (9 g) was consumed with less mastication effort than the standard rice cake (9 g) and with the same effort as the standard (3 g). Both the sample amount and texture influenced mastication, although neither factor caused a significant difference in swallowing characteristics. These observations suggest that swallowing was induced when the bolus properties became suitable for swallowing, as healthy subjects could adjust their mastication technique according to the food amount and texture.

Textural Evaluation of Rice Cake by Chewing and Swallowing Measurements on Human Subjects

A device and a method for measuring a continuous swallowing motion The device comprises a plurality of pressure sensors (111) supportedly arranged in the vertical direction and a pressure sensor mounting device (130) for fixing the pressure sensors in contact with the front jaw part of a test subject The pressure sensor mounting device (130) further comprises a urethane foam (132) supportedly arranged along the vertical motion of a thyroid cartilage in swallowing a food, a pressure sensor fixing device (131) supporting the urethane foam, and a holding band (134) holding the pressure sensor fixing device on the front jaw part of the test subject

Device and method for measuring continuous swallowing motion

A Relation Between the Piezoelectric Pulse Transducer Waveforms and Food Bolus Passage during Pharyngeal Phase of Swallow

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

Evaluation of Swallowing Function by Simultaneous Measurement of Larynx Movement, Electromyogram of Suprahyoid Musculature and Swallowing Sound : Change of Swallowing Motion of Rice Gruel due to the Difference of Its Property

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

Hajime Takahashi

Papers

Evaluation of Swallowing Function by Simultaneous Measurement of Larynx Movement, Electromyogram of Suprahyoid Musculature and Swallowing Sound : Change of Swallowing Motion of Rice Gruel due to the Difference of Its Property

Development of Rice Cracker for Aged People