Based on the fact that soymilk is a colloidal dispersion system where lipid is distributed to the continuous phase which consists of protein, the process for manufacturing low-fat soymilk, separating fat centrifugally from soymilk in order to control fat concentration in the soymilk, was established. With the soymilk which was produced in this process, a fundamental technique to design physical properties of colloidal food by controlling its particle dispersion state was established, and it led to a novel technology to produce tofu and yuba.
Hygienic control of food contact surfaces is important for the prevention of cross-contamination and food poisoning due to Vibrio parahaemolyticus. This study focused on adhesion of V. parahaemolyticus cells to a stainless steel surface as an initial event of the cross-contamination. Stainless steel coupons were artificially contaminated by contact with a cell suspension and soaked in water for different periods of time to enumerate the viable cells remaining adherent on the surface. The adherent viable cells were greatly reduced in 1 min of water soaking, but further water soaking did not completely eliminate the viable cells from the surface. The small part of cells firmly attached to the stainless steel surface was not eliminated even by sonication. The viable cell count on the stainless steel surface after water soaking depended on the cell concentration of bacterial suspension but not on the length of contact time. The results would be useful for confirming the points to control the cross-contamination risk of V. parahaemolyticus.
Two-bite Texture Profile Analysis (TPA) according to the National Criteria for Patients with Difficulties in Swallowing was conducted by using gels with similar taste but different textures. Three textural parameters of ‘hardness,’ ‘adhesiveness,’ and ‘cohesiveness’ were obtained from the TPA profiles. In addition, the velocity of the passage of the same gels through the pharynx was measured by the ultrasonic pulse-Doppler method. The ‘hardness’ parameter correlated best among the 3 textural parameters with the maximum velocity through the pharynx, Vmax, which has been reported to be a good predictor of aspiration risk. The ‘hardness’ parameter and the apparent viscosity μ of bolus increased with increase in sample concentration. From this aspect, the ‘hardness’ parameter was considered to correlate with Vmax. Above a value of 103 N/m2 for the ‘hardness,’ the value of Vmax was similar to that of yogurt, and so the risk of aspiration was considered to be similar to that for yogurt. On the other hand, the ‘cohesiveness’ did not correlate with the velocity through the pharynx.
In the fluidized bed granulation process of powdered food, aqueous solution is usually sprayed as a binder to the powder to grow the granules, however, increase in the moisture content of granules often spoils the product quality and elongates successive drying period. In this study, Steam-Water Tow-Phase (SWTP) binder has been applied for fluidized bed granulation to reduce the amount of water added to the powder. In the SWTP binder granulation, superheated steam and water (127°C, 138 kPaG) were sprayed at 18.8 g/min and 0～40 g/min respectively through a signle-fluid nozzle to the mixed powder of maize starch (800 g) and dextrin (200 g). In the SWTP binder granulation, the amount of water sprayed to the powder decreased to 40～84％ to produce the granules having equivalent size with that obtained by the conventional fluidized bed granulation using the liquid binder. At lower water spraying rates, the reduction effect of binder water increased, however, coarse particles were produced in these conditions. The steam effectively grew the granules by condensing on the nuclear generated by the water droplets, however, the lack of sufficient number of nuclear permitted the steam to increase the ununiformity in granule size.