Comparison of Growth and Freshness Characteristics of ‘Cheongchima’ Lettuce Baby Leaf Vegetables as Affected by CO2 Treatment during Cultivation

The increasing popularity of baby leaf vegetables necessitates advancements in cultivation techniques to enhance growth and ensure quality retention post-harvest. This research evaluated the impact of CO2 treatment on growth and examined factors such as weight, gas exchange, chlorophyll content (SPAD), color, and visual quality during the storage of lettuce baby leaf vegetables. The vegetables were grown in controlled environments with ambient CO2, enhanced by direct gassing or carbonated water at concentrations of 700 and 1,400 mg·L-1. CO2 enrichment during the growth phase significantly promoted fresh weight, plant length, and leaf length compared to untreated plants. Growth analyses showed slight differences in weight and size between CO2-enriched and control plants. However, photosynthetic efficiency (Fv/ Fm) and antioxidant enzyme activity (SOD) showed no significant changes due to CO2 treatment. This study also examined how CO2 treatment affected the quality of lettuce baby leaf vegetables after packaging with polypropylene film at 10oC. In packaging, O2 consumption and CO2 accumulation were higher in CO2-treated plants. CO2-treated plants showed lower values in SPAD, hue angle, and appearance compared to the control. While CO2 treatments improved growth, they did not maintain quality during the shelf-life period