Japanese traditional fermented food “natto” is rich in vegetable protein and is consumed on a daily basis. Japan’s older population is rapidly increasing and therefore, it is important to develop a new natto preferred in the elderly people from a nutritional standpoint. For the development of a new natto, following four aspects are essentially required : (1) soybeans and natto strains, its combination, (2) new manufacturing methods, (3) sauce for natto, (4) types of package. However so far, the studies for improving natto have been mainly focused on the characteristics of natto strains. In the present study, by carefully watching the dietary habits of the elderly people, we have developed the new natto that is consumed conveniently and is popular with them. In addition, we explained the sauce and types of package, for natto. It is hoped that “natto” will be consumed not only in Japan but also in wider areas in the near future.
Molecular-level understanding of ice crystal surfaces holds the key to unlocking the secrets of various fields. To observe ice crystal surfaces at the molecular level, we developed an advanced optical microscope, and succeeded in visualizing individual elementary steps of 0.37nm in height on ice basal faces. Utilizing this microscope, we also attempted to visualize the surface melting processes of ice crystals. We found the presence of two types of surface liquid phases (quasi-liquid layer phases) that exhibit different morphologies and dynamics on ice basal faces.
Recrystallization of ice crystals is a physical cause of deterioration in frozen foods during both storage and distribution, and therefore needs to be controlled and predicted for optimal storage and distribution of frozen foods. However, a systematic understanding of recrystallization is lacking and the accumulation of sufficient recrystallization experiments remains difficult due to the time-consuming storage experiments necessary to investigate recrystallization behavior. In response to this challenge, we showed that the concept of water mobility in a freeze-concentrated matrix is useful for predicting the recrystallization rate of ice crystals in model frozen foods. Thus, knowing the water diffusion coefficient, an index of water mobility, in a freeze-concentrated matrix would enable us to predict the recrystallization rate of ice crystals and limit the need for time-consuming storage experiments.