The Role of Inulin in Maintaining Antioxidant Capacity and Enzymatic Activities of Jerusalem Artichoke (Helianthus tuberosus L.) Cultivars During Cold Storage

Jerusalem artichoke (<i>Helianthus tuberosus</i> L.) is valued for its high inulin content and adaptability to marginal lands. This study investigated the changes in inulin content, antioxidant capacity, polyphenol concentrations, and enzymatic activities of eight cultivars during 60 days of cold storage. Inulin levels ranged from 582.43 g/kg (LZJ006) to 809.70 g/kg (LZJ055), with LZJ047 maintaining the highest content throughout storage. The antioxidant potential, as measured by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, declined across all cultivars, correlating with the reduction in inulin content. The polyphenol content varied significantly, with LZJ119 having 2.17 times more than LZJ010. POD activity increased, while catalase (CAT) and superoxide dismutase (SOD) activities fluctuated during the storage period. Hierarchical Cluster Analysis identified three distinct antioxidant clusters, revealing significant correlations between inulin content and key antioxidant parameters (CAT, FRAP, DPPH). These findings highlight the pivotal role of inulin in preserving the antioxidant system and bioactive properties of Jerusalem artichoke tubers during extended cold storage, providing valuable insights for post-harvest management and cultivar selection.