Differences in Chewing Behavior during Mastication of Foods with Different Textures

Area of Science:

• Oral physiology
• Biomechanics of mastication
• Food science

Background:

• Chewing is a complex process involving muscle coordination to break down food.
• The physical properties of food significantly influence masticatory muscle activity and chewing patterns.
• Understanding how different food textures affect chewing is crucial for oral health and nutrition.

Purpose of the Study:

• To investigate the influence of Japanese staple foods (rice and rice cake) with varying physical properties on masticatory muscle activity.
• To compare the electromyographic patterns of the masseter and suprahyoid muscles during the consumption of rice versus rice cake.
• To elucidate how the masticatory sequence adapts to the initial physical characteristics of different foods.

Main Methods:

• Six healthy adults participated in the study.
• Surface electromyography (EMG) was used to record activity in the masseter and suprahyoid muscles.
• Participants freely chewed standard Japanese rice and rice cake in a natural manner.

Main Results:

• Significant differences in masticatory duration were observed between rice and rice cake.
• Masseter muscle activity per chewing cycle was notably higher for rice cake compared to rice.
• Masseter muscle activity decreased progressively during rice cake chewing, while suprahyoid muscle activity remained constant.

Conclusions:

• The bolus formation process differs substantially between rice and rice cake, reflected in distinct jaw-closing and jaw-opening muscle activities.
• Masticatory sequences adapt to variations in food's initial physical properties.
• This research provides insights into oral physiology, bolus formation, and the impact of food texture on chewing mechanics.