Microencapsulation of ascorbic acid for enhanced long-term retention during storage

A trial to evaluate a range of microcapsules prepared using various encapsulating agents individually and in combination has been completed. The aim was to provide a means of protecting ascorbic acid (AA) from harsh conditions of elevated temperature over extended storage periods, and to obtain a basis for the selection of encapsulating agents for the AA fortification of specialised food products. Microcapsules were prepared using a pilot scale spray dryer; good yields and high recoveries of AA were obtained. The resultant materials were fine powders of relatively uniform particle size, spherical with varying degrees of indentation but no evidence of mechanical damage. Samples of the microcapsules were stored at temperatures of 20, 30, 37 and 48 °C for periods of up to 15 months. There were significant variations in AA retention between treatments and encapsulating agents. It is recommended that six encapsulating agent combinations and loading levels be further evaluated to determine their potential for the fortification of selected food products