Formulation of nano/micodispersion systems via self-assembly and complexation of edible biomolecules were investigated. In this review, results and findings on (1) formulation of fine particle via self-complexation of chitosan and amphiphilic lipid molecules, (2) stabilization of oil-in-water emulsions by the electrostatic deposition using ionic (positively or negatively charged) polysaccharides, (3) efficient preparation of lipid vesicles encapsulating functional molecules, and (4) formulation of microspheres with controlled diameter using biopolymers were summarized. Preparation procedure of these dispersion systems is relatively simple, without high energy input, severe physicochemical stresses, and use of harmful chemicals. The properties of the nano/microdispersion systems, such as particle size, surface charge, dispersion stability and encapsulation/controlled-release properties, could be designed by properties of used biomolecules and preparation conditions. These dispersion systems would be useful for developing novel foods with high quality, advanced functionality, and good stability.
The objective of this study was to find the possibility of hydrostatic pressure treatment (50 MPa, 30℃), and carbon dioxide treatment (1.0 MPa, 40℃). Yudane method uses a dough made by mixing boiling water and flour in addition to those by water. Advantages of this method are unique texture and sugar sweetness generated by endogenous enzymes. On the other hand, by endogenous enzymatic reaction under bacteriostatic pressure, it will be possible to improve the taste as well as Yudane method. By the pressure treatments the increases of reducing sugar, glutamic acid and water-soluble protein were observed and the decreases of gliadin and glutenin were characterized. From the increases of total sugars and amino acids, improvement of taste, fragrant bread crust and promotion of yeast activity can be expected.
To elucidate the influence of acidity regulators on stability using a soymilk colloidal dispersion system, a viscous model was constructed, and its effectiveness was verified. When the pH of soymilk was reduced using ascorbic acid, the apparent viscosity of all soymilk increased significantly at approximately pH 5.8-5.9; this was found to be a universal phenomenon in the soymilk colloidal dispersion system. When the pH decreased after addition of six types of acidity regulators to soymilk, the apparent viscosity behaviors of the samples were similar. Assuming that the bulkiness of the aggregate was proportional to the hydrogen ion concentration in the high pH range, calculations were made by applying the extended equation obtained from the viscosity equation of Einstein and the Krieger-Dougherty equation. A negative correlation was confirmed with the parameter hc representing the degree of bulkiness of the aggregate and the parameter Kc representing the degree of filling state of the gigantic aggregate. Moreover, the macroscopic aggregation behavior was similar, even if the internal structure of the isolated aggregates differed depending on differences in the crosslinking mechanism. Because of the correlations between parameters, this system for soymilk processing may have industrial applications.
Molecular diffusion coefficients are important physical (transport) properties for designing various separation processes such as chromatography and drying. They are also used for understanding the size of molecules. Although several methods can be used for determining the molecular diffusion coefficient Dm, the Dm values for large (modified) proteins, DNA and bio-nanoparticles are not readily available. In this study, Dm values of PEGylated proteins of various molecular weights were measured by using the Taylor dispersion analysis (TDA) method and dynamic light scattering (DLS). Both methods provided very similar Dm values. However, as each method has its own characteristics, limitations and precautions, it is recommended to use both methods as complimentary methods for obtaining reliable Dm values.