Estimation of scavenging capacity of melatonin and other antioxidants: Contribution and evaluation in germinated seeds

•Melatonin shows low scavenger capacity unlike polyphenol compounds.•Germination in edible seeds increases melatonin contents.•Antioxidant capacity improves by polyphenols and melatonin in germinated seeds.•Germinated seeds showed a higher percent of DPPH inhibition respect to raw seeds. Seven edible seeds for the levels of melatonin, phenolic compounds and their antioxidant capacity were evaluated during germination process. Radical scavenging parameters were also studied in standard antioxidants to understand their antiradical actions. Germination brought about significant increases of total phenol compounds in all edible seeds, showing red cabbage, radish and broccoli the highest contents (21.6, 20.4 and 16.4mg GAE/g DW, respectively). The concentration of melatonin is greatly variable in edible seeds, exhibiting significant increases during germination. The highest levels were found in red cabbage (857pg/g DW) radish (536pg/g DW) and broccoli (439pg/g DW). The germinated seeds which had the highest levels of polyphenols and melatonin were those that showed the most relevant antiradical activities (>97%). This information is valuable for the incorporation of red cabbage, radish and broccoli germinated seeds into the diet to promote potential health benefits.