Development of Edible Core-shell Structured Fibers

Abstract

Centrifugal spinning process with duplex tube nozzle for the fabrication of core-shell structured edible fiber was successfully developed. Using maltose enabled fibers to be relatively stable against humidity of air. Fat-soluble materials could be successfully encapsulated by the employment of domain-matrix structure where maltose aqueous solution is continuous phase and oil is dispersed phase. In order to protect encapsulated material from oxidation or leakage, core-shell structured fiber, where domain-matrix structure fibers were enwrapped by maltose shell, was developed. The required condition to obtain core-shell structure was considered based on Hagen-Poiseuille equation, and the ratio of cross section averaged linear velocities of 0.97 was accomplished.

Fluorescent microscopy confirmed the core-shell structure and SEM observation revealed that domain-matrix structure fibers without shell had rough surface probably due to the detachment of domain oil phase, by contrast core-shell structured fibers had quite smooth surface. This may be attributed to the protection from detachment of oil phase by shell material, which was supported by the result of pyrene elution experiment.