Dried Japanese noodles are one of the most favored foods in Japan and are supplied as a preserved food due to its long shelf life. In the production of dried noodles, the drying process governs product quality and is known to be challenging, as the strips of fresh noodles are relatively thick and have limited strength to withstand the internal stress caused by rapid drying. Therefore, controlled humidity drying is necessary to maintain balance between the rates of evaporation and internal moisture diffusion. However, optimal drying conditions are difficult to achieve due to the complexity of operating variables, such as temperature, humidity, and velocity. In the present study, we regarded the drying of fresh noodles as a moisture diffusion phenomenon within a solid material. The moisture diffusivity, the effect of the drying condition on drying kinetics, and the stress induced by drying were investigated to obtain technical information about the optimal drying operation. It is expected that this information will be useful in establishing optimal drying protocols for Japanese noodles.

Bacteriophages (phages) are viruses that infect bacteria. Phages can replicate in host cells and lyse the cells after replication. The antimicrobial potential of phages has been a focus of medical research to combat multi-drug resistance to antibiotics in bacteria. Their use in controlling pathogens in the field of food science is also expected. In the USA and parts of Europe, phage utilization has been approved for inhibiting the growth of foodborne pathogens such as Escherichia coli O157 : H7, Salmonella enterica, and Listeria monocytogenes in food. In this paper, we introduced phage utilization as a novel antimicrobial technology for killing bacteria in food. Some tailed phages belonging to Caudovirales have been used as components of antimicrobial phage products. The phage products targeting E. coli, Salmonella, and L. monocytogenes show effective antibacterial activities in food. However, the antimicrobial effects of phages are not without drawbacks, including the development of phage-resistant strains and the low contact rates between phage and host in food. Phage cocktails are effective for expanding the host range and reducing the emergence of phage-resistant bacteria. Combinations of phage treatment and other preservation technologies can suppress the emergence of resistant strains and further promote food safety.

The aim of this work was to study the effect of Maitake proteases on the textural properties of cooked rice. We also investigated alterations in the molecular weight distribution of proteins and levels of free amino acids in rice after soaking in Maitake extract at 50°C. When rice was soaked and heated with Maitake extract, the texture of cooked rice was softer than rice cooked with water both immediately after cooking and post-refrigeration. Our results showed that when the rice grains were soaked in Maitake extract at 50°C for 60 min, Maitake metalloproteases degraded rice glutelin, resulting in an increased level of hydrophobic amino acids such as phenylalanine, valine, and isoleucine. Moreover, we demonstrated that aspartic proteases from Maitake also degraded the rice proteins, without affecting their SDS-PAGE patterns. Finally, when the rice was cooked with Maitake extract, Maitake metalloproteases decomposed the glutelin and contributed to an apparent decrease in rice hardness.

Fermented barley extract (FBE) was reported to have anti-inflammatory effects. The aim of this study was to identify anti-inflammatory compounds in FBE and elucidate their mechanisms of action. We investigated the effects of compounds isolated from FBE on T cells and chondrocytes at the level of gene and protein expression. As a result, pyroglutamyl peptide (pEPYP) increased IL-10 expression by T cells and decreased MMP-13 expression by chondrocytes. Moreover, pEPYP inhibited paw inflammation in collagen-induced arthritis (CIA) model rats. The serum concentration of anti-collagen type II antibody in the pEPYP group was less than that in the control group, although not significantly. Decreased inflammatory cell infiltration was observed in histopathological specimens of the pEPYP group as compared to the control group. These results suggest that pEPYP contained in FBE suppressed joint inflammation by increasing T cell-derived IL-10 and decreasing chondrocyte-derived MMP-13.

This study investigated the fate of Escherichia coli (E. coli) O157 spiked into 24 commercially available fermented soybean paste (miso) samples. Viable cell numbers of the inoculated E. coli O157 at storage conditions of 5, 10, 20, or 30°C were measured by the agar plate method or most probable number method. Cell numbers of E. coli O157 decreased gradually in all tested samples. The decreases in E. coli O157 numbers depended mainly on the water activity of samples. Decreases in the contamination level of E. coli O157 did not depend on the ingredients of miso samples (malted rice, wheat, and soybean). The obtained results suggest that the commercial risk of accidental E. coli O157 contamination is practically negligible because of high cell mortality during transportation and storage processes at room temperature.

The suitability of ‘Bartlett’ pears and ‘Senryo’ Chinese pears for dried-fruit processing at different degrees of ripening was studied. Dried fruits from the pre-ripened stage and after 5 or 10 days of ripening at 15°C were processed by microwave irradiation pretreatment of the pulp, followed by hot-air drying. The dried fruit from 10-day ripened ‘Bartlett’, the table-ripe stage, had a significantly softer texture and preferred scores for softness and taste compared to the dried fruit from pre-ripened fruit. Ripening did not affect the sensory scores for dried fruit from ‘Senryo’, in most cases. We conclude that a ripening process is necessary for dried ‘Bartlett’, but is not absolutely required for dried ‘Senryo’.

Recently, Japanese food culture, termed Washoku, has drawn a great deal of global attention. Tofu, soy sauce and miso, which are typical traditional foods, are well known not only in Japan but also throughout the world. In particular, the volume of exported miso has shown continued yearly increases. Among misos, rice miso is the most highly produced and is widely distributed nationwide. Soybeans, salt and Koji (malted rice) are used as the major raw materials of rice miso. Light-colored rice miso is generally made from boiled soybeans, whereas deep-red rice miso is made from steamed soybeans. The fermentation process and subsequent aging process produce a mellow fragrance that determines the deliciousness of miso. The 2018 Satellite Luncheon Meeting focusing on soybeans dealt with the flavor components responsible for the taste of miso. Dr. Kumazawa (Ogawa & Co., Ltd.), who is working on the flavor components derived from processed soybean products, presented examples of the relationship between the main components that form the flavor of rice miso and trace components. He also showed alterations in the main and trace components following heat treatment.

The variety of processed food products in Japan is vast compared to the rest of the world; processed soybean foods are no exception. Miso, soy sauce, soy milk, and tofu are the main processed soybean product groups. For processed food products that provide a mellow and attractive flavor, the aroma is one of the most important factors controlling the value of the products, and it is a significant challenge to achieve a high quality aroma with good palatability. Therefore, to create attractive processed soybean food products, fundamental knowledge of the key aroma constituents (potent and off-flavor odorants) in processed soybean foods and their chemical and sensory behaviors is strongly needed. In this article, I will introduce part of our research focusing on the potent odorants and their characteristics in miso as well as the topic of enhancing the effect of saltiness due to aroma.