Application of Appropriate Postharvest Technologies to Benefit the Sweetpotato Industry

The application of appropriate postharvest technologies is required to provide consistent supplies of high quality fresh market and processed sweetpotato products to meet increasing domestic and international market demand. Strong year-round interest in a diversity of fresh and value-added sweetpotato products requires a better understanding of the postharvest physiology of the roots, coupled with the utilization of proper temperature and storage atmosphere management. Long-term storage is necessary for sweetpotato producers to maintain their domestic market position over extended periods of time. The export market is also an expanding segment of the U.S. sweetpotato industry, with Canada and the United Kingdom being the leading international market destinations. Strong partnerships between universities and the private sector have been established to strengthen the growth of the U.S. sweetpotato industry. An increasingly diverse market for processed and value-added sweetpotato products may require different postharvest technology strategies for different products. Regulation of the storage temperature and atmospheric composition allows for manipulation of sweetpotato carbohydrate metabolism, product flavor, and quality. Individual sugar concentrations in sweetpotato roots can be significantly altered by temperature and atmospheric oxygen concentration during curing and storage. Significant increases in sucrose content, the principal sugar in raw roots, occur in sweetpotatoes with decreasing storage temperatures. Increases in the two main monosaccharides, fructose and glucose, also occur with decreasing storage temperature, but to a lesser degree than sucrose. Low atmospheric oxygen concentration during curing and storage enhances sucrose synthesis, but diminishes the synthesis of fructose and glucose. The future for domestic market growth and export market expansion for U.S. sweetpotato products remains bright. Strong research and extension programs covering the entire sweetpotato supply chain, coupled with significant private sector investment in new product development and marketing has continued to advance the sweetpotato industry forward. Utilization of microwavable films to wrap individual roots is an increasingly popular packaging technology which has been adopted to add value and preparation convenience to sweetpotato roots in the retail market sector. Advancements and adoption of appropriate postharvest technologies will allow for year-round supplies of high quality fresh market and processed product forms of sweetpotatoes that will continue to strengthen the industry.