Surface modification of food fiber by dry particle coating

In this study, a new methodology for surface modification of food fibers is proposed via a dry particle coating technology. Basically, in the dry part icle coating processing, a mechano-chemical reaction between hydrophilic OH groups of food fiber and silanol groups-Si(OH)-on the surface of hydrophil ic silica is used, As a result of this reaction, dehydration (H + OA --> H2 O) is expected, leading to suppression of the hygroscopic properties of foo d fibers for the purposes of better handling and enhancement of the preserv ative property. For the dry particle coating, a horizontal particle Composi te equipment with an ellipse shaped rotor was used. The surface of the food fiber was coated with a very fine hydrophilic silica (SiO2) and a mechano- chemical reaction,vas activated by a high shear stress and an impaction for ce in the equipment. The coated powders were prepared under various operati ng parameters of vessel rotational speed and operation time. The surface pr operties of the coated powders were evaluated by angle of repose (flowabili ty), specific surface area, particle size, and a scanning electron microsco py (SEM) observation. The hygroscopic property was analyzed using a water a dsorption method in a temperature and humidity controlled chamber. Interact ion between OH and silanol groups was analyzed by a Fourier Transform Infra red Spectroscopy (FT-IR) method. As a result, the optimum operating conditions for preventing hygroscopic pr operty of food fiber can be determined and the mechanism of the mechano-che mical reaction can be elucidated.