Logistics costs cut by 73% and spoilage brought under control… K-sweet potatoes open a path for ship exports to Thailand

[Korea Agricultural Technology News = Reporter Baek Cheol-hyeon] Korean sweet potatoes, which had long been overshadowed by Japanese products in Southeast Asia’s premium dessert market, have refined innovative technology and opened the full-fledged era of ‘ship exports.’ With the development of a technology that reduces the burden of expensive air logistics costs while actually improving quality, it is being evaluated as having instantly won over the tastes of demanding overseas buyers.

The Rural Development Administration announced that it had established a ship export model applying ‘integrated freshness-preservation technology’ to target Thailand’s top-tier sweet potato market, which had been dominated by Japanese sweet potatoes, and succeeded in developing the local market.

Until now, Korean sweet potatoes had faced a chronic problem of excessively high spoilage rates during long-distance sea transport. As a result, they had no choice but to rely only on costly air distribution, which in turn weakened price competitiveness and became an obstacle to expanding market share in Thailand.

The key solution introduced by the RDA research team to overcome this was the combined application of an ‘improved curing process’ and ‘sweet potato-tailored controlled atmosphere (CA) technology.’

The curing treatment, which had previously been done only once, was expanded to a total of two times—immediately after harvest and after the washing process—to maximize the formation of a protective layer (cork layer) on wounded areas of the sweet potatoes. This fundamentally blocked microbial intrusion. In addition, the internal container environment was precisely controlled to match sweet potato physiology: temperature at 10–12℃, humidity at 75%, oxygen at 5%, and carbon dioxide at 12%, lowering the rate at which the sweet potatoes breathe (respiration rate) during transport.

The effect was dramatic. This demonstration was conducted on two varieties known as ‘honey sweet potatoes,’ and the results showed that 10 days after arrival at the destination, the spoilage rate dropped sharply from 65% to around 8%. For long-term stored sweet potatoes as well, the spoilage rate was suppressed from 86% to 12%. These figures fully meet the famously strict Japanese distribution standard (12% or less after 10 days), achieving ‘zero claims (0)’ with not a single return or complaint throughout the entire process.

The innovation in technology immediately translated into overwhelming price competitiveness. Based on 8 tons, logistics costs that had previously been about 15 million won for air transport were reduced to about 4 million won by switching to ship-based CA transport. This delivered a budget-saving effect of no less than 73%.

Priced about 3,000 won cheaper than Japanese products locally, K-sweet potatoes captured both price and quality, proudly entering 16 branches of ‘Gourmet Market,’ a top-tier department store chain in Thailand, and selling out completely within a month. 

The response from local buyers was also enthusiastic. A Thai buyer who highly valued the technology signed a regular contract requesting sweet potato exports on the scale of 48 tons annually. In addition, the buyer strongly requested that Korean strawberries, which had previously been imported entirely by air, also be shipped by sea using this technology, and the two sides swiftly agreed to pursue a pilot shipment this coming December.

Ahn Uk-hyeon, director of the Export Agricultural Technology Division at the Rural Development Administration, said, “This achievement is a leading R&D outcome that simultaneously overcame the burden of rising logistics costs and the chronic spoilage problem of sweet potatoes,” adding, “Starting with sweet potatoes, we will apply and advance freshness-preservation technology across our fresh agricultural products that are highly preferred in overseas markets, further elevating the status of K-food in the global market.” He also added, “To revitalize exports, we will work closely with aT so that support can be provided smoothly.”