Antioxidant activity of Rhizostoma pulmo proteins. SP, Aqueous soluble proteins; IP, Insoluble proteins; JC, jellyfish collagen; VC, vertebrate (bovine) collagen. SP > 30, Soluble proteins with MW > 30 kDa; SP 10–30, Soluble proteins with MW 10–30 kDa; SP 3–10, Soluble proteins with MW 3–10 kDa; PHp 10–30, pepsin hydrolysed proteins with MW 10–30 kDa; PHp 3–10, pepsin hydrolysed proteins with MW 3–10 kDa; PHp < 3, pepsin hydrolysed proteins with MW < 3 kDa; HJCp 10–30, hydrolysed jellyfish collagen with MW 10–30 kDa; HJCp 3–10, hydrolysed jellyfish collagen with MW 3–10 kDa; HJCp < 3, hydrolysed jellyfish collagen with MW < 3 kDa; HVCp 10–30, hydrolysed vertebrate collagen with MW 10–30 kDa: HVCp 3–10, hydrolysed vertebrate collagen with MW between 3 and 10 kDa; HVCp < 3, hydrolysed vertebrate collagen with MW < 3 kDa. Data are the mean values of six independent experiments performed in three technical replicates. The antioxidant activity is expressed as nmol of TE per mg of protein ± standard deviation. Student’s t-test * p < 0.05, ** p < 0.01 and *** p < 0.001.