Crunchy even after 90 days of storage for spring cabbage… RDA’s ‘active CA’ eases summer cabbage supply

[Korea Agricultural Technology News = Reporter Baek Cheol-hyeon] An innovative storage technology capable of solving the recurring ‘summer highland cabbage crisis’ caused every August and September by scorching heat waves and sudden torrential rains has completed field demonstrations and is now moving into full-scale distribution. The technology is the ‘active CA (Controlled Atmosphere) storage technology’ developed by the Rural Development Administration. Because it can preserve spring cabbage until midsummer while maintaining the same freshness as at harvest, it is drawing attention as a key solution to chronic summer instability in the supply of horticultural produce.

The Rural Development Administration said it will continue advancing the ‘active CA storage technology,’ which enables long-term fresh storage of spring cabbage through midsummer, and will install four additional units this year at key hubs including agricultural stockpiling bases.

Cabbage is a crop that is difficult to store long term because it continues to respire and age even after harvest. While conventional CA storage maintained oxygen and carbon dioxide concentrations at preset fixed levels, the newly developed ‘active CA storage technology’ is a more advanced system that precisely measures in real time the air emitted by cabbage (its respiration rate) and automatically adjusts the environment inside the storage facility.

The results were overwhelming when researchers built a 100㎡ active CA storage facility last year at the Boeun agricultural products processing center (APC) in North Chungcheong Province and verified its effects by storing 90 tons of spring cabbage harvested in June from Goesan, Mungyeong and other areas for about three months.

Cabbage kept in ordinary cold storage lost as much as 14.2% of its weight over 90 days, whereas cabbage stored with active CA declined by only 2.65%, retaining about 80% of the moisture present immediately after harvest. 

In addition, in comparisons of tissue firmness, ordinary cold-stored cabbage fell to about two-thirds of its initial level (2.2 N/㎜), but active CA-stored cabbage maintained a condition almost identical to immediately after harvest (3.3 N/㎜), preserving its characteristic crisp texture.

The ‘processing yield,’ meaning output relative to input during kimchi processing, was found to be 49%, which is 6 percentage points higher than the processing yield of ordinary cold-stored cabbage or summer highland cabbage (43%), and was assessed as likely to contribute significantly to improving profitability in the kimchi processing industry.

To maximize use of the storage facilities, the Rural Development Administration established a ‘year-round rotational storage model by alternating crops,’ storing spring cabbage from June to September and apples from November to May of the following year. The idea is to reduce idle periods for expensive facilities and raise annual utilization rates.

The government had distributed a total of six units in the field by last year, including Boeun APC (4 units), Goesan Hanuri Farming Association (1 unit), and Sancheong Joy Farm (1 unit). This year, it plans to install four more units at Jangseong stockpiling base (2 units), Seomungyeong Agricultural Cooperative (1 unit), and Aramgol Farming Association (1 unit). In the future, it plans to expand application beyond apples and cabbage to various horticultural products and upgrade the system into an ‘intelligent storage system’ that diagnoses the physiological condition of agricultural products on its own and controls the environment accordingly.

Lim Jong-guk, head of the Postharvest Management Engineering Division at the Rural Development Administration, said, “Because agricultural products continue to breathe even after harvest, if they are stored with precise air control, the freshest produce can be provided to consumers when needed. Active CA storage technology will become a key means of supporting stable agricultural supply and meeting the needs of both consumers and farmers at the same time.”