Phytonutrients and Metabolism Changes in Topped Radish Root and Its Detached Leaves during 1^◦C Cold Postharvest Storage

Glucosinolates, lipid-soluble vitamins E and K contents, primary metabolites and plant hormones were analyzed from topped radish root and detached leaf during storage at 1^◦C. The topped root was analyzed at 0, 5, 15, 30, and 90 days after storage while the detached leaf was analyzed at 0, 5, 15, 30, and 45 days in an airtight storage atmosphere environment. The results showed that aliphatic glucosinolates were gradually decreased in leaf but not in root. There was a highly significant correlation between tryptophan and 4-methoxyindoleglucobrassicin in both tissues (r = 0.922, n = 10). There was no significant difference in vitamins E and K in leaf and root during storage. Plant hormones partially explained the significantly changed metabolites by tissue and time, which were identified during cold storage. Phenylalanine, lysine, tryptophan, and myo-inositol were the most important biomarkers that explained the difference in leaf and root tissue during cold storage. The most different metabolism between leaf and root tissue was starch and sucrose metabolism. Therefore, different postharvest technology or regimes should be applied to these tissues.