Utilization of pulsed infrared for the rapid semidrying of fresh ginseng with advanced qualities and extended shelf life

Abstract

Various physiological functionalities of ginseng have been proven, however, there are little investigation on the characteristics of semidried ginseng as a foodstuff. This study aimed to investigate the effects of hot air (HA) drying temperatures and infrared (IR) pulse sizes on the drying rate of fresh ginseng and to evaluate the optimal semidrying conditions for fresh ginseng. The pulsed IR accelerated drying of ginseng compared to HA, and particularly the drying rate of IR, was rapid at the early drying stage. Dryness (moisture content) affected the rehydration properties, and ginseng dried at relatively high HA temperatures or IR treatments showed high rehydration capacity (RC) and low reconstitution (RE). The color and cutting force were affected by the dryness of ginseng rather than the drying method, and a moisture content of 0.7 kg/kg solid was regarded as the optimal semidrying condition for fresh ginseng. When applied to chicken porridge, semidried ginseng showed a lower cutting force than completely dried ginseng, and the cutting force of semidried ginseng by IR did not differ from that of the fresh control. The total viable count (TVC) indicated that semidrying by IR could extend the shelf life of ginseng by more than twice that of the fresh control. Therefore, pulsed IR has the potential to replace HA drying to produce semidried ginseng with fresh ginseng-like quality characteristics.