Chewing sounds are an important component contributing to the perceived "deliciousness" of food. This study clarified the tonal and emotional evaluations elicited solely by chewing sounds, excluding the influences of taste, aroma, and texture. The participants comprised 25 employees of a company affiliated with the first author. A total of 22 types of food, including frozen desserts and sweets, were evaluated by the SD method. Principal component analysis revealed that 83.7 % of the tonal evaluation variance was explained by the first principal component, which ranged from "hard/cracked" to "vague/weak". Similarly, 79.9 % of the emotional evaluation was explained by the first principal component, which ranged from "motivating/arousing" to "depressed/calm". A strong correlation was observed between the scores of the first principal component and the tonal and emotional evaluations (r = 0.984). Cluster analysis grouped the chewing sounds into four clusters: high arousal, semi-arousal, semi- subsidence, and high subsidence. Metallic and hard sounds tended to evoke feelings of motivation and arousal, whereas weak and vague sounds were associated with depression and subsidence. Spectrogram analysis indicated that metallic and hard chewing sounds produced high sound pressure levels in high frequency bands over short durations, while weak sounds produced low sound pressure levels in low frequency bands over longer periods. These findings suggest that differences in food structure affect both the tonal and emotional perceptions of chewing sounds.

This study aimed to develop konjac glucomannan gels with novel mechanical properties by modifying the gel network structure. Five types of scallop shell–derived particle gelling agents, with varying particle diameters (1.4 mm < D_a ≤ 4.0 mm, 910 μm < D_b ≤ 1.4 mm, 530 μm < D_c ≤ 910 μm, D_d ≤ 310 μm, and D_e ≤ 150 μm), were used as alternatives to conventional gelling agents (e.g., calcium hydroxide). Konjac gels with an inhomogeneous structure, characterized by cloudy and translucent regions, were obtained using gelling agents with large particle sizes (530 μm < D_a, D_b, and D_c ≤ 4.0 mm). Puncture resistance, surface pH, and internal pH were measured. The cloudy regions exhibited puncture resistance values ranging from 0.63 N to 0.90 N, whereas the translucent regions showed values below the measurement accuracy of 0.05 N. The pH values showed no significant difference (11.62 ≤ pH ≤ 12.34) among all samples regardless of the measurement regions.Although the pH values of the translucent regions were sufficiently alkaline for gel formation, puncture resistance showed markedly low values. Two-bite texture analysis showed distinct mechanical property differences between the inhomogeneous and homogeneous konjac glucomannan gels.

To elucidate the potential novel functions and health benefits of red beet, the present study compared the antioxidant properties, polyphenol contents, and flavor characteristics of kimchi prepared with red beet and Japanese radish. Samples of red beet kimchi and Japanese radish kimchi that had been fermented for 0, 3, 7 and 14 days were analyzed. In all samples, DPPH radical scavenging activity and total polyphenol content were consistently higher in red beet kimchi than in Japanese radish kimchi. The results of sensory evaluations revealed that red beet kimchi was sweeter and less acidic than Japanese radish kimchi, suggesting that red beet kimchi may be preferred by people who dislike acidic kimchi. Furthermore, red beet kimchi had higher functionality and appeared to be more palatable than Japanese radish kimchi.