Yukimuro means “snow room” in Japanese and has been used to preserve vegetables and other foods under low temperature by using natural energy. Here we investigated the effectiveness of snow utilization for the storage of wheat flour. Strong and whole grain flours were packed into paper bags and stored for three months under three different conditions: at room temperature, in a cold refrigerator, and in a moist cold snow room (i.e., yukimuro) and provided for analyses. As compared with the samples stored at room temperature, both cold storage in refrigerator and moist cold storage in snow room reduced lipid peroxidation and generation of free fatty acid. The wheat flours stored in yukimuro showed better bread-making properties than those stored at room temperature or in refrigerator. The brown bread made from the flours stored in yukimuro showed better sensory evaluation scores. These findings indicate that moist cold storage in snow room (yukimuro) suppresses lipid oxidation and improves bread-making properties of wheat flours.
Progressive freeze-concentration (PFC) of blueberry juice was carried out by a tubular ice system and the original juice at 11.2 Brix was concentrated up to 27.2 Brix. The PFC-concentration was proved to give a high quality concentrate with no substantial change both in organic acid distribution and flavor profile. The PFC-concentrated blueberry juice was fermented to produce a blueberry wine with 11.1 vol-% alcohol content, showing that a high alcohol content can be obtained without chaptalization in the present method. After the fermentation, some changes were observed both in the organic acid distribution and the flavor profile. As a whole, however, the blueberry wine retained enough amount of original blueberry flavors. The present results suggest a possibility to produce a new-type blueberry wine with rich ingredients and flavors.
The number of occurrences of foreign objects in food is becoming less frequent. However, it is very difficult to remove small foreign objects such as hair and soft plastics in food. In this paper, the results of an experimental study of the performance of a new electrostatic separator of small foreign objects in dried food are presented. The separator consists of an inclined rotating drum, which is grounded, a cylindrical electrode fixed at the center of the drum and a suction device. The principle of the separation is based on the difference in the charge per unit mass of the dried food and foreign objects. Separation tests were performed on two types of mixtures. The effects of operating parameters, such as the applied voltage and the angular speed of the drum, on the separation efficiency were examined. In the separation of a mixture of plastic fragments and dried lettuce, the recovery rate of the lettuce was greater than 96% for a purity of 100%. In the separation of a mixture of hairs and dried lettuce, the recovery rate of the lettuce was greater than 94% for a purity of 100%.
Intake of probiotics is effective in the development of intestinal flora. Generally, addition of living microbes to the intestine is important for the regulation of the intestinal functions and growth inhibition of pathogenic bacteria. However, probiotics such as lactic acid bacteria do not always survive in the stomach. Lactic acid bacteria are useful as a probiotic, thus their death in the stomach decreases their beneficial effects. Konjac is an indigestible high-fiber food. In the present study, we examined the effect of konjac on the survival of lactic acid bacteria. Lactobacillus crispatus and Lactobacillus plantarum strains were taken to globular konjac, which had large surface area by including bubble. Subsequently, the konjac was soaked in artificial gastric juice（pH 1.2）. The lactic acid bacteria without konjac survived when incubated for 30 min but not 60, 90, or 120 min, whereas L. crispatus and L. plantarum with konjac survived even when incubated for 60 and 120 min, respectively. Therefore, the present study suggests that the survival of lactic acid bacteria improves on co-incubation with konjac. In addition, the probiotics may be able to access the intestines regardless of the kind of bacterial species.
This study focused on the processed food products, using raw okara (a food product developed to mitigate problems associated with mass disposal of soy waste). To examine the heating condition effectively, we simulated food qualities during heating. Color change was treated as a first-order reaction, and kinetic parameters (Ea = 61.6 kJ/mol，Z = 4.93×105 1/s) were calculated by Golden section method. Moisture content was calculated via mass transfer analysis, based on Fick’s laws of diffusion. Our simulation predicted values for color, moisture content, water activity, and texture that were in good agreement with experimental values. We determined that, to achieve an equivalent to a commercial product, it was suggested that about 1/2 could shorten heating time by changing surface temperature from 80℃ to 120℃. Thus, this simulation technique can contribute to the shortening of heating times for processed food products.