상용 아미노산 종류별 처리에 따른 ‘청상추 ’의 생육 및 수확후 품질 변화 : 유공 PE 필름 포장 하 4℃ 저장 조건 특성 평가 = Influence of Different Commercial Amino Acid Treatments on the Growth and Postharvest Quality of ‘Cheongchima’ Leaf Lettuce: Characterization under Perforated Polyethylene (PE) Film Packaging and 4 C Storage Conditions

다국어 초록 (Multilingual Abstract)

This study investigated the effects of different amino acid-based fertilizers on the growth and postharvest quality of leaf lettuce (Lactuca sativa L. cv. ‘Cheongchima’). Three formulations were evaluated: a monosodium glu- tamate (MSG)-based amino acid solution prepared from food-grade crystals, a fermentation by-product–derived com- mercial liquid fertilizer, and a collagen hydrolysate–based liquid fertilizer containing supplementary nutrients such as nitrogen, potassium, and calcium. Lettuce plants were cultivated under rooftop conditions, and growth characteristics and postharvest parameters were assessed under 4°C refrigerated storage in perforated polyethylene (PE) film packaging for 14 days. Results indicated that the MSG-based amino acid solution slightly delayed leaf yellowing and maintained chlo- rophyll content (SPAD values) during storage under perforated PE film packaging, although its effect on fresh weight accumulation was limited. The fertilizer derived from fermentation by-products exhibited the lowest growth and chlo- rophyll levels, likely due to residual salts or organic acids that inhibited early growth. In contrast, the collagen hydro- lysate–based fertilizer promoted vigorous vegetative development and produced the highest fresh weight and SPAD values during both cultivation and storage. Across all treatments, the effectiveness of amino acid fertilizers varied depend- ing on raw material composition and processing methods. The MSG-derived formulation showed potential for practical use in leafy vegetable production, but yield enhancement may require combined application with mineral nutrients. Mean- while, complex nutrient formulations such as the collagen hydrolysate fertilizer were more effective in improving both growth performance and postharvest quality. These findings demonstrate that amino acid fertilizers can serve as prom- ising biostimulant resources for sustainable and resource-circulating agriculture, while also highlighting the potential of food-grade MSG as an alternative agricultural input.