A two-dimensional video-based motion analysis software was used to measure the angle of upper limb joints of people during their kitchen knife handling, and differences in upper limb movement based on their skill levels were examined. The results showed that skilled people began cutting with their shoulders extended and elbows bent; subsequently, they cut by bending their shoulders and extending their elbows, while moving their upper arms forward using the shoulders as pivot and moving the forearm-hand-knife in parallel and forward-downward directions without radial flexion of their hands. Unskilled people bent their shoulders less than did skilled people during cutting; through extension of their elbows or radial flexion of their hands, they exerted pressure by moving the forearm-hand-knife downward. Reduced shoulder bending during cutting results in increased downward movement of the ulnar styloid. Thus, awareness of shoulder posture may aid in efficiently mastering knife-handling skills.

The Japanese soup stock "dashi" is the basis of the Japanese food culture. We prepared and studied handmade bonito-kelp stock and instant different types of packet bonito-kelp stocks. We analyzed the biochemical components in the stocks: free amino acids, nucleic acids compounds, and organic acids. Our aim was to elucidate the tastes of Japanese stock by the factors of taste activity value (TAV), equivalent umami concentration (EUC), principal component analysis (PCA) and sensory analysis. The traits of handmade stock and packet stocks were confirmed through PCA. The handmade stock and packet stocks could easily be distinguished by the human volunteers. The handmade stock was significantly preferred compared to the four types of packet stocks. The handmade stock and packet stocks all featured multiple tastes with different biochemical components, including aspartic acid, glutamic acid, inosine monophosphate, adenosine monophosphate, and acetic acid. The concentrations of biochemical components differed between handmade stock and all four packet stocks. The data indicate that multiple biocomponents explain the tastes of "dashi".