Extension of ginger shelf-life using a forced evaporation humidifier.

An above-ground, pilot storage facility (15 m(2)) that utilizes a forced evaporation humidifier was developed, and its performance was evaluated for long-term storage of gingers. The forced evaporation humidifier was able to evenly maintain the temperature of the storage space at 12 +/- 1 degrees C with 95-99% relative humidity without condensation. Weight loss occurred in all treatment groups using forced humidification during 12 months of storage. Groups with polypropylene bag packing lost 12-15% of their weight, which was lower than that lost by the group loaded onto plastic crates (22-32%). After four months of storage, a control group treated with ultrasonic humidification was terminated because of its high rotting rate (84-88%). In contrast, rotting rates of all the forced evaporation humidifier treatment groups was <17% after 12 months of storage, Which was significantly lower than that for gingers stored in underground caves with about 30% losing rates that have environments that are difficult to control. Lightness (L) and yellowness (b) values and the hardness of ginger peels decreased with storage time, while values for cross sections of flesh remained similar or decreased slightly compared to initial values. While free sugar content gradually declined with storage time, b values remained similar to the initial b values observed in the present study, this suggests that the reduction in free sugar content had no significant effect on ginger browning. Therefore, we conclude that if gingers are stored in an above-ground storage facility capable of maintaining optimal humidity with a forced evaporation humidifier and are cured prior to packing into bags, the storage period can be effectively extended, and that this storage system could replace the existing underground cave storage method.