The result of the WiKim-RDA joint research reveals that the storage life of the kimchi cabbage can be extended by up to five months.

WiKim, whose the Acting General Director is Dr. Hak-Jong Choi, has developed a pallet unit controlled atmosphere (PUCA) designed to significantly extend the storage period of kimchi cabbage, the primary ingredient of kimchi. This research initiative was a collaboration between WiKim and the Rural Development Administration (RDA), whose an Administrator is Kyeongkyu Kim.

What is a controlled atmosphere (CA) storage? It refers to a technology through which the storage life of agricultural products can be extended by controlling the atmospheric conditions within the storage container to suppress the respiratory activity and physiological changes of agricultural products.

Pallet unit CA storage system

WiKim’s pallet unit CA storage system connects to several airtight containers installed in a general cold storage facility with a nitrogen generator, a high-pressure carbon dioxide container, and an air hose. This system individually controls the internal concentrations of oxygen and carbon dioxide for each container through a programmable logic controller (PLC). In particular, this technology is ideal for storing small quantities of multicategorized agricultural products and makes it easier to control the timing of shipment for these products.
※ Programmable logic controller (PLC): A device that integrates the functions of varying relays, timers, and counters so that such functions can be controlled by a microprocessor-based program

The WiKim-RDA joint research team applied the new system to winter kimchi cabbages in an effort to identify the optimal atmosphere conditions for storage. The results show that the newly developed CA storage system extends the product’s storage life by up to five months, which is significantly greater compared to that of general cold storage (three months).

When the kimchi cabbage was stored at a low temperature (0°C) for 150 days, the optimal conditions, which resulted to the least damage on the cabbages, happened when the concentrations of oxygen and carbon dioxide inside the airtight container were maintained at 2 ± 0.5% and 5 ± 1%, respectively. Furthermore, the moisture content of cabbage leaves stored at low temperature without atmosphere control decreased by 6.5%, while that of CA-stored cabbage leaves decreased by less than 1%.

In addition, the hardness, solid soluble content, and chromaticity of CA-stored kimchi cabbages remained at their initial storage levels. For glucosinolate, its content was 86% higher than that of cold-stored cabbages.

Pallet unit CA storage packaging system

On-site application of the pallet unit CA storage system

Manufacturers can have a stable supply of cabbage and can produce high-quality kimchi, thanks to the CA storage system. This system also allows them to reduce processing waste generated during the selection process and, thus, increase production quantities.

WiKim’s pallet unit CA storage system features cheaper initial installation and maintenance costs than the existing CA storage facility. Thus, the pallet unit CA system is expected to contribute to the stabilized supply and demand of the kimchi cabbage for each season by providing ideal storage solutions to kimchi manufacturers and cold storage facilities.

On June 3, Leessine Food, a kimchi manufacturer located in Gwangsan-gu, Gwangju, held a meeting intended to evaluate the pallet unit CA storage system for storage life extension of kimchi cabbage.

Stakeholders such as kimchi processing companies, cabbage producers, distributors, universities, and research institutions participated in the on-site evaluation meeting, where the pallet unit CA storage system was introduced, and the results of the quality survey on winter kimchi cabbage stored in the system were discussed. Subsequently, sensory evaluation and discussions on the prototypes of kimchi made with the CA-stored kimchi cabbage were conducted.

The results of this study were published in the April 2020 issue of Scientia Horticulturae, an international journal publishing research related to horticultural crops.
※ Title of thesis: Development of multi-pallet unit load storage system with controlled atmosphere and humidity for storage life extension of winter kimchi cabbage (Brassica rapa L. ssp. pekinensis)