Effects of textured food masticatory performance in older people with different dental conditions

Physiological deterioration (aging, poor dental status, and reduced tongue pressure) makes chewing difficult. This study aimed to investigate the chewing patterns of older people with or without dentures, evaluate the textural and masticatory properties of texture-modified radish Kimchi, and investigate the correlation between dental status and tongue pressure. Additionally, differences in the subjective–objective concordance of texture-modified Kimchi were investigated using the preference test.

This study included 32 Korean women aged between 65 and 85 years. Masticatory behavior was recorded by electromyography, and tongue pressure was measured using the Iowa Oral Performance Instrument. A preference test, with hardness as the relevant textural property, determined the participants’ preferences among the test samples (food with a homogeneous structure—radish Kimchi). To assess preference differences, a questionnaire suitable for older people was designed. The preference for cooked radish Kimchi with various blanching times based on overall acceptability and self-reporting of preference was investigated to develop elderly-friendly food. The subjective scores indicated whether the sample (radish Kimchi) was hard or soft based on the chewing ability of the participants. Dental status, muscle activities, and tongue pressure were considered for the food design with optimized texture. The relationship between subject score and mastication properties were examined using multiple regression analysis.

The number of chews and chewing time increased with hardness, significantly activating the masseter and temporalis muscles. The evaluation of masseter muscle activity, particularly for level-6 radish Kimchi, showed that older people with complete dentures chewed less actively than those with natural teeth (p < 0.05). The older people with natural teeth (18.94 ± 10.27 kPa) exhibited higher tongue pressure than those with complete dentures (10.81 ± 62.93 kPa), and the difference was statistically significant (p < 0.01). Older people preferred food with familiar tastes and textures. An association was found between the subjective hardness score and the objective hardness level. The perceived hardness intensity was linked to the chewing ability of the participant. Denture wearers exhibited a lower chewing ability, and at level 6, they perceived greater hardness of food than those with natural teeth.