Lipid oxidation processes in bulk, micelle, O/W emulsion and micoencapuslated systems were observed. Oxidation of lipid in O/W emulsion and micoencapuslated systems proceeded more slowly for the smaller oil-droplets. Models for describing the characteristics in the processes were proposed based on the kinetic equation of autocatalytic type. Alkyl glycosides were synthesized through β-glucosidase-catalyzed condensation in an aqueous-organic biphasic system, and esters consisting hydrophilic and hydrophobic moieties were also synthesized through lipase-catalyzed condensation in a microaqueous organic solvent system. Models which describe physicochemical phenomena occurring in the systems were proposed, and the factors affecting the product yields were quantitatively analyzed based on the models.
The market for vegetable juice was growing rapidly, but it has been stagnant for a few years. Therefore, we attempted to develop a new type of vegetable juice, which is kept the natural flavor of vegetable. We consider a new way of thermal sterilization because the flavor of vegetable can be changed a lot by the thermal sterilization process. As a result, a new technology, steam infusion, was established, and a new type of vegetable juice “Yasai-Shibori” was introduced in the market in 2009.
The physical properties of food hydrocolloids are a reflection of their inner structure. In this study, we reviewed several methods for examining the inner structure of food hydrocolloids; the percolation model, dielectric analysis, and fractal analysis. In addition, we reviewed the application of food hydrocolloids in developing special foods for patients with dysphagia. The percolation model was effective for describing the behavior of the rheological properties of food hydrocolloids near the sol-gel transition point. The dielectric properties of food hydrocolloids such as bovine serum albumin solution, gelatin solution, and alginate solution were analyzed. Each dielectric relaxation observed was considered ascribable to a different movement of “components” in the electric field among different hydrocolloid systems, thus giving information about the inner structure of the hydrocolloids. Fractal analysis (self-similar structure) is a quantitative analytical method for characterizing many types of disordered shapes. The elastic behavior of the aggregate gels observed on heating globular protein solutions was confirmed to be a reflection of the fractal structure of aggregates in the gels. We investigated the effect of rheological properties of food hydrocolloids on the velocity of the bolus by using ultrasonic pulse Doppler method. Viscosity (μ), dynamic viscosity (η′), and complex viscosity (η*), were considered suitable indices for liquid-type foods for patients with dysphagia.
Microsoft Excel® is most popularly used spreadsheet software. Although figures can be drawn using the software, their quality seems to be unsatisfactory for the use in scientific papers or reports. The quality can be improved using Microsoft PowerPoint®, which is also software in Microsoft Office® and is widely used as a presentation tool. A rough figure is prepared based on the data in the Excel, and it is modified to fine one using the PowerPoint. It will be explained how to draw fine figures using both the software.
It is practically important to understand glass transition temperature (Tg) of dry food products for their quality control. Tg of food products has been often investigated by using differential scanning calorimetry (DSC). However, there is little report on Tg of cookie products. This may be because DSC thermogram shows intricate thermal response. In order to understand Tg of cookie, thermal rheological analysis (TRA) which has a similar principle to thermal mechanical analysis was established, and softening behavior of cookie related to glass transition was investigated. Preliminarily, inulin was employed as a standard material, and relationship between Tg and softening temperature (Ts) was investigated. Glass transition and softening of inulin sample were clearly observed by DSC and TRA, respectively. The Ts was directly proportional to the Tg. On the other hand, cookie sample showed no apparent glass transition in the DSC thermogram, but TRA showed clear softening reflecting glass transition. The Ts decreased with increase in the water content because of plasticizing effect of water. This result was useful for prediction of the water content which cookie softens at room temperature.
The interaction between soybean 7S globulin and the carboxyl groups of cation-exchange resins of the carboxylate type was analyzed by using a surface plasmon resonance (SPR) technology with relevance to deamidation of the globulin. This interaction and the degree of deamidation were measured under conditions of buffered solutions of different salt, sodium ion concentration, and pH. Soybean 7S globulin was dissolved in various solutions and mixed with cation-exchange resins of the carboxylate type. After removal of the resins, the degree of deamidation of the soybean 7S globulin was measured. The affinity of soybean 7S globulin dissolved in various solutions for the carboxyl group was analyzed with a SPR biosensor (Biacore) by using a chip with carboxylates on a dextran matrix. The deamidation level of soybean 7S globulin and the affinity of soybean 7S globulin for the polymer-supported carboxylates were well correlated. Both of them became higher at lower sodium concentrations and were highest at pH 6.0. Among the buffers examined, the phosphate buffer was the most effective for deamidation of soybean 7S globulin; and the affinity of soybean 7S globulin in this buffer for the carboxylate groups on the SPR chips was the highest in the phosphate buffer. Therefore, deamidation of 7S globulin protein would effectively occur when the amide groups of glutamine and asparagine residues of the protein interact with the carboxylates on resins.
Fluidized bed granulation is widely used to improve flowability and solubility of various kinds of powdered food products. Aqueous solution is usually sprayed to the powder to grow the granules in the process, however, increase in the moisture content of granules often spoils the product quality and elongates successive drying period. This study investigated effects of binder spraying rate (10～40 g/min) and binder atomizing air pressure (0.05～0.25 MPa) on the moisture balance of the fluidized bed and the granule growth to determine the preferable binder spraying condition for mixed powder of maize starch (800 g) and dextrin (200 g). Although the amount of binder that evaporated without binding the particles increased as the binder spraying rate increased, the ratio of the evaporated binder to the amount of totally sprayed binder decreased from approximately 60% to 30%. The pressure of binder atomizing air had no effect on the powder moisture content. The amount of binder required for the granulation decreased at faster binder spraying rate and lower atomizing air pressure, however, coarse particles were produced in these conditions. At lower binder spraying rate, spherical and uniform size granules were produced.
We made a re-expanded version for the database of thermal death of microorganisms, ThermoKill Database (TKDB) R8110. The database was built using data adopted and collected from research papers published between 1981 and 2010 in 25 major selected academic journals. The database includes thermal death data such as 20,467 D values and 3,272 z values along with predicted D values at reference temperatures, other microbial information, environmental conditions and bibliographic data for a total of 70 items. Representative statistical distribution data obtained from the novel database were demonstrated and discussed the significance of its practical use in food industry.