Table 4. Antioxidant activity of peptide from by-product fisheries and aquaculture

By product source Protease / peptide extraction Scavenging activity(Activity value or IC50 at certain condition i.e. sample concentration or certain degree hydrolysis)
DPPH Hydroxyl radical
Abalone Haliotis discus hannai viscera (Zhou et al., 2012) Alkali protease IC50; 7 mg/mL IC50; 10 mg/mL
Neutral protease IC50; 4 mg/mL IC50; 11 mg/mL
Papain IC50; 4 mg/mL IC50; 17 mg/mL
Pepsin IC50; 4 mg/mL IC50; 5 mg/mL
Trypsin IC50; 4 mg/mL IC50; 23 mg/mL
Arrow squid Nototodarus sloanii pen (Shavandi et al., 2017) Bacterial endopeptidase (HT) 40%-45%; 4 mg/mL NA
Trypsin 40%-45%; 4 mg/mL NA
Pepsin 35%-40%; 4 mg/mL NA
Squid Ommastrephes bartrami (Song et al., 2016) Endogenous protease IC50; 0.231 mg/mL IC50; 0.74 mg/mL
Salmon Salmo salar skin (Zhang et al., 2022) Alcalase NA 70%-80%; 4 mg/mL
Neutrase NA 50%-60%; 4 mg/mL
Flavourzyme NA 30%-40%; 4 mg/mL
Protamex NA 40%-50%; 4 mg/mL
Rainbow trout Oncorhynchus mykiss skin (Yaghoubzadeh et al., 2020) Alcalase 40%-45%; 0.8 mg/mL NA
Flavourzyme 45%-50%; 0.8 mg/mL NA
Tuna dark muscle (Saidi et al., 2018) Prolyve BS 30%-35%; 2 mg/mL 35%-40%; 2 mg/mL
Tuna Thunnus tonggol dark muscle (Hsu, 2010) Orientase 31.5%; 3 mg/mL NA
Protease XXIII 41.0%; 3 mg/mL NA
Striped weakfish Cynoscion guatucupa skin and bones (Lima et al., 2019) Alcalase 50%-60%; hydrolysis at 10% DH 70%-80%; hydrolysis at 10% DH
60%-70%; hydrolysis at 15% DH 40%-50%; hydrolysis at 15% DH
Protamex 50%-60%; hydrolysis at 10% DH 30%-40%; hydrolysis at 10% DH
50%-60%; hydrolysis at 15% DH 40%-50%; hydrolysis at 15% DH
IC50, half maximal inhibitory concentration; DPPH, 2,2-diphenyl-1-picrylhydrazyl; HT, protein/protease prepared from bacteria using high-throughput preparation; NA, not available; BS, Prolyve BS. A neutral enzyme composed of metalloprotease produced by fermentation using a selected strain of Bacillus subtilis.; DH, degree of hydrolysis.