A Powderization Process for Encapsulating with Functional Biomaterials Using Nozzleless Electrostatic Atomization

Powderization of oils has been used as a method to enhance the stability of polyunsaturated fatty acids. Previously, we successfully powderized soybean oil via nozzleless electrostatic atomization. The process of nozzleless electrostatic atomization process was applied to the one-step process of encapsulating oil in wall materials. The encapsulation of oils in powder is dependent on the wall materials. The present study aimed to resolve the behavior of oil encapsulated in particles using a novel method of electrostatic atomization, and to investigate the effect of wall materials on the oil content in the encapsulated formulations. The size of particles surrounding oil was dependent on the type of wall materials used for encapsulation, and the oil content within the encapsulation decreased with increase in particle size. Furthermore, wall materials with higher hydrophobicity increased the oil content within the encapsulation, as more hydrophobic particles could absorb the oil more effectively. PRACTICAL APPLICATION: Nozzleless electrostatic atomization is a new method for preparing encapsulation of oil using various wall materials.

Effect of different dextrose equivalents of maltodextrin on oxidation stability in encapsulated fish oil by spray drying

Encapsulating fish oil by spray drying with an adequate wall material was investigated to determine if stable powders containing emulsified fish-oil-droplets can be formed. In particular, the dextrose equivalent (DE) of maltodextrin (MD) affects the powder structure, surface-oil ratio, and oxidative stability of fish oil. The carrier solution was prepared using MD with different DEs (DE = 11, 19, and 25) and sodium caseinate as the wall material and the emulsifier, respectively. The percentage of microcapsules having a vacuole was 73, 39, and 38% for MD with DE = 11, 19, and 25, respectively. Peroxide values (PVs) were measured for the microcapsules incubated at 60 °C. The microcapsules prepared with MD of DE = 25 and 19 had lower PVs than those prepared with MD of DE = 11. The difference in PV can be ascribed to the difference in the surface-oil ratio of the spray-dried microcapsules.

Dispersion and oxidative stability of O/W emulsions and oxidation of microencapsulated oil

Oil-in-water (O/W) emulsions are among the dispersion systems commonly used in food, and these emulsions are in thermodynamically unstable or metastable states. In this paper, various methods for preparing O/W emulsions are outlined. Since the commodity value of food is impaired by the destabilization of O/W emulsions, experimental and theoretical approaches to assess the stability of O/W emulsions are overviewed, and factors affecting the dispersion stability of emulsions are discussed based on the DLVO theory and the concept of the stability factor. The oxidation of lipids in O/W emulsions is unhealthy and gives rise to unpleasant odors. Factors affecting the autoxidation of lipids are discussed, and theoretical models are used to demonstrate that a reduction of the oil droplet size suppresses or retards autoxidation. Microencapsulated lipids or oils exhibit distinct features in the oxidation process. Models that explain these features are described. It is demonstrated that a reduction in the oil droplet size is also effective for suppressing or retarding the oxidation of microencapsulated oils.

Engineering aspects of rate-related processes in food manufacturing

Many rate-related phenomena occur in food manufacturing processes. This review addresses four of them, all of which are topics that the author has studied in order to design food manufacturing processes that are favorable from the standpoint of food engineering. They include chromatographic separation through continuous separation with a simulated moving adsorber, lipid oxidation kinetics in emulsions and microencapsulated systems, kinetic analysis and extraction in subcritical water, and water migration in pasta.