Postharvest Handling and Marketing Management for Making High Salability of Sweetpotatoes

상품성 제고를 위한 고구마 수확 후 관리 및 출하기술

The qualities including taste of sweetpotato stored during the winter which can display in the spring market in Korea are affected by availability of storage for the roots. In order to make high storage availability of sweetpotato, the postharvest handlings should be done thoroughly from the moment of harvest until shipping them to the market. A lot of procedures that must be handled carefully for improving postharvest management are as follows; digging, trimming, gathering, putting in storage containers, carrying them from field to house, curing, storing, washing, drying, selecting marketable roots, packing and shipping to the market, etc.. Sweetpotatoes have a high moisture content, and a relatively thin and delicate skin, and are sensitive to chilling, so careless postharvest handling can lead to both quantitative and qualitative losses which may be extremely high in some circumstances. From now on research has concentrated on the improvement of postharvest conditions to increase yield and lower disease rates. Storage, which makes sweetpotatoes available through out the year, benefits both the producer and the consumer. Seven very important points must be needed in order to get the best quality marketable roots in the storing of sweetpotatos : $\circled1$The storage house must be clean and sanitary, $\circled2$The crop must be harvested before the first frost to avoid low-temperature injury, $\circled3$Particular care must be taken to avoid cutting, bruising, or other injuries of the sweetpotatoes during digging, picking up, grading, placing in containers, and moving to the storage house, $\circled4$Select sound, disease-free roots for storage $\circled5$Sweetpotatoes should be stored in properly stacked containers $\circled6$Cure immediately after harvest, preferably at 32∼33$^{\circ}C$ and 90 to 95 percent relative humidity for 4 to 7 days, After curing the temperature should be reduced to 13$^{\circ}C$ to 16$^{\circ}C$ by ventilating the storage with outside air. $\circled7$Store at 12$^{\circ}C$ to 14$^{\circ}C$ and a relative humidity of 80 to 85 percent. Storage houses should be located on suitable sites and should be tightly constructed and insulated so that temperature and humidity will be uniform. Sweetpotatoes are usually not washed and graded, and lately sometimes washed, graded, waxed, before being shipped to market. Consumer packaging of sweetpotatoes in paper boxes(10-15kg) or film bags is done mainly to aid marketing. The shelf life of washed roots in consumer packs in only 1 to 2 weeks. Weight loss of roots during marketing is much less in perforated film bags than in mesh and paper bags. Perforation of 0.8 to 1kg polyethylene bags with about six 6mm holes is essential ; to lower the internal relative humidity and avoid excessive sprouting, rooting, and dampness. Development and use of better postharvest handling with good storage facilities or marketing methods can minimize sweetpotate losses and has an effect of indirectly increasing productivity and farmer’s income.