Characterization and comparative analysis of saponins in various spinach (Spinacia oleracea L.) cultivars according to growing seasons - Su-Yeon Lee; Doo-Young Kim; Hyun-Jae Jang; Seon Min Oh; Hyoung-Geun Kim; Jongmin Ahn; In-Seo Heo; Heung Joo Yuk; Eun Kyoung Seo; Sei-Ryang Oh; Hyung Won Ryu (Food Chemistry, 2025)