Kuzu-mochi made from fermentation treated wheat starch is a traditional Japanese sweet from the Edo period. Kuzu-mochi has a unique texture, which is not found in wheat starch gels. In this study, to clarify the texture characteristics of kuzu-mochi, the physical properties of kuzu-mochi were compared with that of various gelatinous foods such as dango, warabi-mochi, and yokan. Kuzu-mochi was softer than yokan, but it was as hard as dango. The chewiness and the stickiness of kuzu-mochi were lower than that of dango. Kuzu-mochi had an elastic texture and not a sticky one. Many starch granules were observed within the gel matrix of kuzu-mochi. The gelatinous state of starch in kuzu-mochi is suggested to contribute to the texture and the internal structure of kuzu-mochi. The firmness of the fermented wheat starch gels was lower than that of kuzu-mochi. After storing for 72h at 4℃，the firmness of the fermented wheat starch gel underwent few changes. The results of this study suggest that the texture of kuzu-mochi is characterized by fermented wheat starch.

　In this study, the growth characteristics of Listeria monocytogenes in commercially supplied ready-to-eat foods (RTEFs) were investigated. The tested RTEFs were a seafood product, Kanifumi-kamaboko (imitation crab surimi product; KK), and a vegetable product, Asazuke-Hakusai (lightly pickled Chinese cabbage; AH), both these foods are available in Japan. Four strains were used for inoculation in these RTEFs: L. monocytogenes ATCC 19115, 99023, LC-8, and LC-21. These strains produced upto 10⁷-10⁹ CFU/mℓ in tryptic soy broth at 20, 10, and 4 ℃. The viable cell count and L. monocytogenes cell count in KK were more than 10⁷ CFU/g at 4, 10, and 20 ℃ in 20, 6, and 2days, respectively. The viable cell count in AH were more than 10⁷ CFU/mℓ in 4 days at 20 ℃ and in 8days at 10 ℃, but there was no significant change in the viable cell count at 4 ℃. In contrast, the viable L. monocytogenes counts in AH decreased to about 2 log CFU/g after 4 days at 20 ℃, and to about 1 log CFU/g after 10 and 20 days at 10 ℃ and 4 ℃, respectively. These results show that while viable counts increased during preservation, L. monocytogenes count decreased. These findings indicate that lactic acid bacteria proliferate during preservation and they produce organic acids that repress the growth of the Listeria in AH.

　We developed a method for quantitatively detecting non-typhoidal Salmonella (NTS) in food using the DOX^TM system. The system was able to detect low concentrations (approximately 1 log CFU/mℓ) of ten strains of NTS, and could not detect moderate concentrations (approximately 3 log CFU/mℓ) of 32 strains belonging to 26 non-Salmonella species examined in this study. The detection time and bacterial count for the ten NTS serotypes had a good, linear calibration curve (correlation coefficient (r) was ＞0.93). We carried out a recovery examination by inoculating samples of 5 meats with S. Enteritidis, Infantis, and Typhimurium, and each sample was examined five times. Total of 150 examinations as all 5 meats inoculated with a medium concentration (2 to 3 log CFU/mℓ) and low concentration (1 to 2 log CFU/mℓ) of the 3 NTS serotypes showed positive. Each three serotypes were detected in 24 of the 25 examinations inoculated with an ultra-low concentration of bacteria (＜1 log CFU/mℓ), and the detection time for positive samples was 680～988 min. The average detection time of S. Enteritidis, Infantis, and Typhimurium were 772 min, 753 min and 787 min, respectively. The DOX system may be a useful tool for establishing the presence of NTS at levels of more than 250 CFU/25 g in food and environmental samples at food processing companies. However, additional validation studies comparing the DOX system and other available official methods are needed.