Table 2.
Description of methods and results of the antioxidant capacity of bioactive peptides produced from plant biomass.
| Systems | Antioxidant methods | Metal chelation | Results | Ref. |
|---|---|---|---|---|
| In vitro (solution) | ORAC, ABTS | NI | Antioxidant activity increased after simulated gastrointestinal digestion, but further hydrolysis of digested hydrolysates with Alcalase did not improve the activity. Highest hydrolysate activities were ABTS (IC50 = 1.16 ± 0.09 mg/mL) and ORAC value of 0.308 ± 0.007 μg Trolox/μg sample. ORAC (IC50) for peptides were AWEEREQGSR (6.7 μg/mL) > YLAGKPQQEH (16 μg/mL) ~ IYIEQGNGITGM (17 μg/mL) ~ TEVWDSNEQ (20 μg/mL) | (Orsini Delgado et al., 2011, and Delgado et al., 2016) |
| In vitro (solution) | ORAC, ABTS | NI | The hydrolysate presented a higher (~2-fold) antioxidant capacity than isolate proteins. ORAC (IC50 = 0.058 ± 0.027 mg/mL TE) and ABTS (IC50 = 2.1 ± 0.3 mg/mL TE). | Sabbione et al. (2016) |
| In vitro (solution and linoleic acid model system) | DPPH, SRSA, HRSA, FRAP, and linoleic acid oxidation (PV) | Fe | Small peptide size (MW < 1 kDa) and high level of hydrophobicity seemed to be important for DPPH, SRSA, HSRA and FRAP. Peptides had better metal chelating properties than GSH but significantly lower FRAP, SRSA, HRSA and DPPH. | Ajibola et al. (2011) |
| In vitro (solution) | FRAP, DPPH, SRSA, HRSA | Fe | Fraction with MW < 1 kDa improved antioxidant activity. GSH exhibited better antioxidant activity in all assays. Fraction showed 65.15% chelating effect on Fe2+ at 0.50 mg/mL, much lower than EDTA. | Xie et al. (2008) |
| In vitro (solution) and in cellulo | DPPH, ABTS | NI | The peptide fractions obtained by Alcalase hydrolysis had the best antioxidant capacity. | Wen et al. (2018) |
| In vitro (solution) | DPPH, SRSA, HRSA, FRAP, | Fe | The activity increased with MW of peptides, except for DPPH results. Pepsin hydrolysate and its fractions did not show any metal chelating activity. Fractions with MW (5–10 kDa) of trypsin showed the highest metal chelation (90%). | Arise et al. (2016) |
| In vitro (solution) | DPPH, SRSA, HRSA, FRAP | Fe | Alcalase hydrolysates exhibited excellent Fe2+ chelating activity and strong DPPH and HRSA capacities. The large-sized peptides (MW > 10 kDa) possessed stronger DPPH activity and reducing power, whereas small-sized peptides (MW < 1 kDa) were more effective in Fe2+ chelating and HRSA. | Xia et al. (2012) |
| In vitro (solution) | DPPH, FRAP, SRSA | Fe | Large-sized peptides (MW > 10 kDa) exhibited strong DPPH, FRAP and SRSA capacities. Low MW fractions (1–5 kDa and <1 kDa) displayed comparable, even lower, EC50 chelation activities than EDTA (0.45 mg/mL). | Bamdad & Chen (2013) |
| In vitro (solution and linoleic model system) | FRAP, TPC (FC), linoleic acid oxidation (PV) | NI | Partially purified C hordein demonstrated the most powerful reducing activity in comparison with those of B and D hordeins. Yet, hydrolysates of hordein fractions and rice bran protein fractions using Pepsin and Trypsin, showed much greater antioxidative activity and reducing power than the original proteins. | Chanput et al. (2009) |
| In vitro (solution, β-carotene/linoleic acid model system) | Inhibition of β-carotene bleaching, FRAP, ABTS | Fe/Cu | Highest antioxidant activity in the smaller MW fractions. A1 and B1 had the highest copper chelating activity (78% and 82%, respectively), while iron chelating activity was the highest in fractions A1 and B3 (36% and 16%, respectively). A2 and B3 had the highest FRAP capacity and inhibition of β-carotene bleaching, while the highest ABTS activity was found in A3 and B3. Phaseolin is the major contributor to the antioxidant and copper chelating activities of the hydrolyzed protein. | Carrasco-Castilla et al. (2012b) |
| In vitro (solution) | DPPH, ABTS | NI | Hydrolysate from pepsin showed higher DPPH activity than protein concentrate and Alcalase hydrolysate. Opposite results were obtained with ABTS activities. | Evangelho et al. (2017) |
| In vitro (solution) | ABTS | NI | The highest ABTS activities were 11.55 mmol/L TEAC/mg protein for P. lunatus Flavourzyme hydrolysate and 10.09 mmol/L TEAC/mg protein for P. vulgaris Alcalase hydrolysate. | Torruco-Uco et al. (2009) |
| In vitro (solution) | ABTS | NI | Hydrolysate with Alcalase–Flavourzyme was the most active with a TEAC of 8.1 mM/mg sample. The TEAC value for Pepsin–Pancreatin hydrolysate was 6.4 mM/mg sample. | Betancur-Ancona et al. (2014) |
| In vitro (solution) | DPPH, ABTS | NI | The DPPH activity values of hydrolysates ranged from 24 to 44% (0.0146–0.027 mmol/L TEAC/mg protein). The best treatment was Azufrado Higuera/Alcalase. ABTS was ranging from 50.2 to 99.9% (1.903–3.788 mmol/L TEAC/mg protein). The treatment Regional ‘87/Alcalase was the more effective | Valdez-Ortiz et al. (2012) |
| In vitro (solution) and In cellulo | TPC (FC) and free radicals scavenging capacity in Caco-2-cells | Fe/Cu | Phaseolin and lectins have 18% and 32% of Fe2+ chelating activity. The lectin and phaseolin hydrolysates, especially the latter, had higher copper and iron (81%) chelating activity. The highest antioxidant activity in cells was found in the hydrolysates of whole protein isolates. | Carrasco-Castilla et al. (2012a) |
| In vitro (solution) | FRAP, ABTS | NI | Lower MW fraction (<3 kDa) showed the highest antioxidant (ABTS and FRAP assays). | Ngoh & Gan (2016) |
| In vitro (solution) | ABTS, HRSA | NI | Free radical scavenging activities was accentuated by in vitro digestion, especially after 2 h Pancreatin following the 1 h Pepsin treatment. Fractions IV, V, VI enriched with di-, tri- and tetrameric peptides containing Trp and Pro exhibited the strongest activity. Dominant existence of Trp in fraction VI suggested that it had an antioxidant activity. | Ma et al. (2010) |
| In vitro (solution) | ABTS | Fe | The MW < 3 kDa fraction after 2 h of hydrolysis by Alcalase had the strongest ABTS (EC50 = 229 μg/mL) and iron chelating (EC50 = 89 μg/mL) activities. It retained its radical scavenging activity after simulated GI digestion and thermal treatments. | Chai et al. (2019) |
| In vitro (solution and linoleic acid model system) | DPPH, inhibition of linoleic acid oxidation (PV) | NI | The radical-scavenging activity of water/salt-soluble extracts from sourdoughs was significantly higher than that of chemically acidified doughs. The highest activity was found for whole wheat, spelt, rye, and kamut sourdoughs. Almost the same results were found for the inhibition of linoleic acid autoxidation. | Coda et al. (2012) |
| In vitro (solution) | DPPH, ABTS, ORAC | NI | The lunasin exhibited a weak DPPH activity (no IC50 value), but a strong ABTS activity (IC50 = 1.45 g/L) and ORAC value (40.06 mol/L TE/g protein when the concentration was 3.20 g/L). | (Ren et al., 2017) |
| In vitro, cooked ground beef and in vivo | DPPH, ABTS, FRAP, meat lipid oxidation (TBARS) | NI | Hydrolysates can effectively inhibit lipid oxidation in food models. F3 inhibited lipid oxidation in meat and presented small peptides (MW < 3 kDa). F2 fraction (3 kDa < MW < 10 kDa) also inhibited lipid oxidation in the highest concentration. F2 and F3 had the greatest DPPH values compared to the hydrolysates and fraction F1 (MW > 10 kDa). F2 and F3 prepared using Alcalase performed better in ABTS, followed by the Alcalase-Flavourzyme sequential system and, lastly, Flavourzyme. | Silveira Coelho et al. (2019) |
| In vitro (solution) and in cellulo | FRAP, DPPH, CAA | NI | F1, F2 and F3, showed a relatively low activity in comparison to BHT. Subfractions from F1 did not show reducing power. F2C, F2D, F3D and F3E were the most active fractions, with a significant increase in reducing power, comparable to BHT. | Torres-Fuentes et al. (2015) |
| In vitro (solution and linoleic acid model system) | DPPH, SRSA, HRSA, FRAP, linoleic acid oxidation (PV) | NI | The lipid peroxidation inhibitory ratio of Fra.IV (81.13%) was closer to that of α-tocopherol (83.66%) but lower than that of BHT (99.71%). Fra.IV had the strongest antioxidant activity compared with the other three fractions. | (Li et al., 2008) |
| In vitro (solution and linoleic acid model system) | DPPH, HRSA, SRSA, linoleic acid oxidation (PV) | Fe/Cu | The lipid peroxidation inhibitory ratio of fraction 7 was 88.81% at the 8th day, which was higher than α-tocopherol (58.85%). The Cu2+ and Fe2+ chelating capabilities of 76.92% and 63.08%, respectively, were lower than EDTA (at 50 μg/mL). | (Zhang et al., 2011) |
| In vitro (solution and linoleic acid model system) and in cellulo | DPPH, ABTS and SRSA, FRAP, linoleic acid oxidation (PV). | NI | GSQ exhibited significant scavenging antioxidant activities and cellular protective effect against oxidative stress. The reducing power of GSQ was lower than that of GSH. | Hong et al. (2014) |
| In vitro (solution) | ORAC | NI | The albumin and globulin hydrolysates showed higher ORAC values than their whole protein counterparts (3-fold increase). The glutelins presented a higher antioxidant potential but did not improve after hydrolysis. | Ortiz-Martinez et al. (2017) |
| In vitro (solution) | SRSA | NI | The fermentative hydrolysate possessed better solubility and antioxidative activity. The antioxidant activity increased (from 10.28 to 259.21%) with fermentation time (from 0 to 32 h), the soluble protein content (from 5.16 to 24.95 mg/mL) and the solubility of the fermentative hydrolysate (from 29.78 to 74.16%). | (Zheng et al., 2012) |
| In vitro (solution and linoleic acid model system) | DPPH, SRSA, HRSA, FRAP, inhibition of linoleic acid oxidation (PV) | NI | Hydrolysate from corn gluten meal possessed the same in vitro antioxidative activities as the zein hydrolysate. EC50 values were about 1.27 and 1.26 mg/mL (DPPH), 12.82 and 12.49 mg/mL (SRSA), 0.81 and 0.80 mg/mL (HRSA), respectively. | (Li et al., 2010) |
| In vitro (solution and linoleic acid model system) | DPPH, FRAP, inhibition of linoleic acid oxidation (PV) | Fe | Alcalase hydrolysate had the highest DPPH (16.67 ± 0.67%), chelation (39.32 ± 0.25%), lipid peroxidation inhibition (34.06 ± 1.62%) and reducing power. F2 exhibited the highest activity, and GHKPS was responsible of the antioxidant activity. | Zhuang et al. (2013) |
| In vitro (solution) | DPPH | NI | The DPPH inhibition of peptide fraction (30 kDa > MW > 10 kDa) treated by pulsed electric field increased 32.1%, compared to the sample untreated. Thus, this technology could improve the antioxidant activity of antioxidant peptides. | (Wang et al., 2014) |
| In vitro (solution) | DPPH, ABTS, HRSA | Fe | QQPQPW exhibited EC50 values of 0.95 (DPPH), 0.0112 (ABTS) and 4.43 (HRSA) mg/mL. It also exhibited notable reducing power of 0.54 (Abs 700 nm) at 2.0 mg/mL, but showed weaker Fe2+ chelating capacity (EC50 = 6.27 mg/mL). | (Wang et al., 2014) |
| In vitro (solution) | SRSA | NI | Hydrolysate showed similar increasing trend as with protein contents until hydrolysis of 10 min and then decreased as hydrolysis time increased. FPLEMMPF exhibited a SRSA of 78.1 U/ml. | (Zheng et al., 2006) |
| In vitro (solution) | DPPH, HRSA, SRSA, FRAP | NI | The antioxidant activities of hydrolysate are highly correlated to small peptides and content of antioxidative amino acids. The IC50 values obtained were 1.42 mg/mL (DPPH), 41.83 mg/mL (HRSA), 26.60 mg/mL (SRSA), and 3.37 mg/mL (FRAP). | (Zhou et al., 2015) |
| In vitro (solution) and in vivo | SRSA. SOD, GPx and MDA measurement | NI | Peptides with low MW exhibited higher antioxidant activities compared to high MW peptides. | (Liu et al., 2015) |
| In vitro (solution) | DPPH, SRSA, HRSA, FRAP | Fe | The hydrolysate (Alcalase + Flavourzyme) exhibited the best antioxidant activities. CSQAPLA exhibited good reducing power and excellent scavenging capacities with IC50 values of 0.116 (DPPH) and 0.39 mg/mL (SRSA). | Jin et al. (2016) |
| In vitro (solution and linoleic acid model system) | DPPH, HRSA, ABTS, SRSA, inhibition of linoleic acid oxidation (PV) | Fe/Cu | Hydrolysates with MW < 10 kDa exhibited the highest antioxidant activities in all relevant assays. F3 exhibited the highest antioxidant action. IC50 of peptides LPF, LLPF, FLPF were 2.07, 2.22 and 1.51 mM (DPPH); 2.70, 2.11 and 2.83 mM (ABTS); respectively. In addition, these peptides effectively inhibited lipid peroxidation in the linoleic acid model system. | Zhuang et al. (2013) |
| In vitro (solution and cooked ground beef) | ORAC, DPPH, lipid oxidation (TBARS) | Fe | ORAC values of hydrolysates varied between 65.6 and 191.4 μmol TE/g. F3 produced by neutral protease possesses the highest activity. DPPH of fractions varied between 18.4 and 38.7 μmol TE/g. F2 and F3 produced by alkaline protease showed the strongest activity. F3 (>1 kDa) from Neutral Protease was the only fraction that inhibited lipid oxidation in ground beef at 250 and 500 μg/g. Fractions exerted modest chelating activities (0.15–0.43 mg EDTA equivalents/g). | (Zhou et al., 2012) |
| In vitro (solution) | DPPH, ABTS, FRAP | Cu | The ABTS of hydrolysate was decreased by 27% after Pepsin treatment but was fully recovered after Pancreatin digestion. DPPH was lower than ABTS activity and showed a 7-fold reduction following Pancreatin treatment. The reducing power of hydrolysates increased 2-fold after Pancreatin digestion. Cu2+ chelation was reduced by Pepsin but was reestablished after Pancreatin treatment. Activities of hydrolysates (1–8 mg/mL) was comparable to, or exceeded, that of 0.1 mg/mL of ascorbic acid or BHA. | (Zhu et al., 2008) |
| In vitro (solution) + in cellulo | DPPH, ORAC, cytotoxicity and CAA on HepG2 cells, ESR. | NI | Peptides AGLPM and HALGA showed significantly better ORAC capacities than AGIPM and HAIGA. ESR showed that the AGLPM and HALGA peptides had strong abilities to scavenge hydroxyl radicals. | Jiang et al. (2018) |
| In vitro (solution) + in cellulo | HRSA, SRSA, ABTS, ORAC, CAA, intracellular ROS clearance capacity | NI | CPF1 (MW < 1 kDa) and CPF2 (1 kDa < MW < 3 kDa) exhibited good HRSA, SRSA, ABTS and ORAC values (CPF1 was slightly higher). YFCLT exhibited excellent ABTS activity (EC50 = 37.63 μM), but was much lower than that of Trolox. | (Wang et al., 2015) |
| In vitro (solution and liposomal system) | FRAP, ABTS. Liposome oxidation (PV, TBARS) | Fe/Cu | Nonhydrolyzed zein was incapable of sequestering either copper (Cu2+) or ferrous (Fe2+) ions. Marked enhancement of the Cu2+ chelation activity of hydrolysates; but no significant improvement in the Fe2+ binding ability. Hydrolysates possessed strong Cu2+ chelation ability and marked reducing power that were accentuated with hydrolysis time. | Kong & Xiong (2006) |
| In vitro (solution) | DPPH, ABTS, SRSA | NI | Hydrophobic amino acids contributed to the DPPH activity, whereas hydrophilic residues were responsible for the ABTS activity. Low MW peptides had stronger activity to prevent SRSA but high MW had stronger DPPH and ABTS activities. | (Tang et al., 2010) |
| In vitro (solution and linoleic model system) | DPPH, ABTS, FRAP, linoleic acid oxidation (PV) | Fe/Cu | Alcalase hydrolysate with the lowest MW fraction (<3 kDa) had the best activity. Iron chelation was high, whereas the copper chelation was very poor. PF and LPF were the active peptides with DPPH of IC50 = 3.2 mM and 2.07 mM, and ABTS of IC50 = 3.37 mM and 2.7 mM. | (Tang and Zhuang, 2014) |
| In vitro (solution) | ORAC | NI | The ORAC values were 426.7 and 783.8 μmol TE/g for hydrolysate and its fraction (MW < 3 kDa), and 250.6 and 500.8 μmol TE/g after cooking. Fractions had better ORAC values, and cooking reduced activity. | Marques et al. (2015) |
| In vitro (solution) | ABTS, DPPH, FRAP | Fe/Cu | The ABTS values of the hydrolysates ranged from 14.3 to 15.1 mM/mg of sample, while DPPH ranged from 86.3 to 98.2% (Pepsin-Pancreatin). FRAP were similar and equivalent to BHT. Alcalase hydrolysate of Vigna unguiculata had the highest chelating activities 70.1% (Fe) and 71.4% (Cu), while Pepsin-Pancreatin hydrolysates had the lowest, ≤49.2%. | Segura-Campos et al. (2013) |
| In vitro (solution) | ABTS | NI | ABTS values were not significantly different between hydrolysates (~14 TE mmol/L/mg). Decreasing MW increased ABTS values. The highest capacity was obtained with MW < 1 kDa with Flavourzyme (2830 TE mmol/L/mg). | Segura Campos et al. (2010) |
| In vitro (solution) | ABTS, DPPH, HRSA | Fe | Antioxidant activity increased after proteolysis. Trypsin hydrolysate showed higher DPPH (38.41 ± 0.02%), ABTS (40.15 ± 0.19%) and metal chelating (35.11 ± 0.05%) activity as compared to Pepsin. Smallest fraction with MW < 3 kDa (F3) possessed the highest DPPH, ABTS, HRSA and chelation activities. | Agrawal et al. (2019) |
| In vitro (solution) | DPPH, SRSA | NI | Short peptides with 2–10 amino acids exhibit significant antioxidant activity than their parent proteins or large polypeptide. Tyr, Leu, His, Gly and Pro were involved in the antioxidant activity of identified peptides. | Amadou et al. (2013) |
| In vitro (solution) | ABTS, SRSA, FRAP | Fe | Hydrolysis slightly increased antioxidant activities. Alcalase and Pancreatin were the best hydrolysates with ABTS ~0.22 mmol TE/g, SRSA ~35 μmol TE/g, FRAP ~0.23 mmol Fe2+/g, and 70% of Fe2+ chelation capacity at 1.54 mg/mL. | Karamać et al. (2016) |
| In vitro (solution) | ORAC, FRAP | NI | The most antioxidant fraction comprised only small size peptides (MW < 1.5 kDa). Potent reduction capacity of GFPGRLDHWCASE (3.20 ± 0.24 μmol TE/μmol), higher than BHA (2.43 μmol Trolox equivalents/μmol). | Silva et al. (2017) |
| In vitro (solution and linoleic acid model system) and chicken patties | HRSA, DPPH, linoleic acid oxidation (PV), lipid oxidation (PV, TBARS) | NI | HRSA and DPPH activity increased drastically after hydrolysis. The fraction with MW > 8 kDa had the strongest scavenging activity on DPPH, HRSA, and antioxidant activity on chicken products (effect similar to BHT). | (Zhao et al., 2014) |
| In vitro (solution) and in cellulo | DPPH, ABTS, cytotoxicity, CAA | NI | C2 showed the most potent antioxidant activities. ADGF demonstrated the strongest radicals scavenging activity, but still lower than ascorbic acid. | (Liu et al., 2018) |
| In vitro (solution) + in vivo (TAC, SOD, CAT, Tpx) | DPPH, HRSA, SRSA. | Fe | The hydrolysate was able to scavenge up to 52%, 32% and 2% of the DPPH, hydroxyl, and superoxide radicals, respectively. DPPH value was similar to GSH, while HRSA and SRSA results was lower. It exhibited moderate metal chelation activity. | (Girgih et al., 2014) |
| In vitro (solution) | DPPH | Fe | At 0.5 mg/mL, WVYY and PSLPA were the most active antioxidant peptides with 67% and 58% DPPH scavenging activity, and metal chelation activity of 94% and 96%, respectively. | (Girgih et al., 2014) |
| In vitro (solution) and in cellulo | HRSA, SRSA, DPPH, FRAP | NI | IC50 values (DPPH, SRSA, HRSA) of the MAR-treated fractions were significantly lower than hydrolysate. At 10 μg/mL, A4a increased cell survival for 60%. | (Lu et al., 2010) |
| In vitro (solution and linoleic acid model system) | ORAC, DPPH, HRSA, SRSA, FRAP, and lipid oxidation (PV) | Fe | Compared to hydrolysate, fractions had higher DPPH, HRSA, SRSA activities, but similar metal reducing, chelating activities, and ability to inhibit linoleic acid oxidation. F2 and F6 were the most active in SRSA (F2 and F6), HRSA (F2), FRAP (F6), and metal chelation (F2 and F6) activities. | (Girgih et al., 2013) |
| In vitro (solution) + in cellulo | DPPH, ABTS, FRAP, ORAC, induced oxidative damage in HepG2 cells | Fe | VNP had only strong ORAC activity (1.5 μmol TE). YGD exhibited high abilities in ABTS (0.95 μmol TE) and ORAC (1.2 μmol TE). In FRAP, YGD and VNP exhibited low abilities. In chelation assay, they exhibited ~0.5 μmol TE. In the cell model, VNP and YGD exert antioxidant effect. | Jiang et al. (2019) |
| In vitro (solution and linoleic acid model system) | DPPH, HRSA, FRAP, linoleic acid oxidation (PV) | Fe | The MW < 1 kDa and 5 < MW < 10 kDa fractions exhibited significantly highest ability to scavenge DPPH, inhibition of the peroxidation of linoleic acid and the reduction of Fe3+ to Fe2+. | Mundi & Aluko (2014) |
| In vitro (solution) | TPC (FC), ABTS, FRAP, TAC (reduction of MoVI), CAA | Fe | Soaking decreased ABTS, TAC, FRAP and chelation activity in all legumes. Cooking of the soaked seeds led to further decrease. Protein digestion increased ABTS and TAC of legumes. The scavenging and reducing activities were correlated with TPC. The potential can be summarized as horse gram > lentils > white pea > black pea > green gram > cowpea > chickpea. | Jamdar et al. (2017) |
| In vitro (solution), in cellulo and in vivo | HRSA, ORAC, cytotoxicity, CAA | Fe | The activities of MW < 3 kDa and 3 kDa < MW < 10 kDa fractions were generally higher than those of MW > 10 kDa. The highest ORAC value was 1452 μmol TE/g for MW < 3 kDa. For the ferrous ion chelation rate, the <3 kDa and 3–10 kDa MW fractions achieved over 90% at 1.2 mg/mL, whereas the >10 kDa MW was lower than 80%. | (Ren et al., 2018) |
| In vitro (solution) | DPPH, HRSA, FRAP | Fe | MW < 1 kDa increased DPPH by 67.77%, 3 kDa < MW < 5 kDa increased HRSA by 44.15%, 5 kDa < MW < 10 kDa increased FRAP (0.153 mmol Fe2+). Hydrolysate and the 5 kDa < MW < 10 kDa fraction showed no metal chelating ability, while 3 kDa < MW < 5 kDa showed inhibition up to 11%. | Aderinola et al. (2019) |
| In vitro (solution) + in vivo | ABTS, FRAP | NI | Pepsin–Pancreatin hydrolysate was the most active in ABTS (102.8 mM/mg TE) and in FRAP (IC50 = 67.2 g/mL). The fraction MW < 1 kDa was the most active (709.8 mM/mg TE) and a FRAP (IC50 = 54.9 g/mL). | Herrera Chalé et al. (2014) |
| In vitro (solution) and in cellulo | DPPH, ABTS, cytotoxicity, CAA | NI | F5 (1.4 kDa > MW > 0.3 kDa) showed the best antioxidant activity. RDY showed higher DPPH and CAA activities in comparison to SVL and EAVQ. SVL, EAVQ and RDY have synergistic antioxidant effects. | Sun et al. (2019) |
| In vitro (solution) | DPPH, HRSA, SRSA, FRAP | Fe | Highest antioxidant potential for the lowest MW fractions. F4 (MW < 1 kDa) exhibited the highest DPPH, along with HRSA and SRSA activities (54 and 65.1%), but moderate activity for FRAP (0.102 mmol Fe2+/g protein) compared to other fractions and the hydrolysate. Chelation activity was generally weak, except for F4 (43.94% at 5 mg/mL). | Sonklin et al. (2018) |
| In vitro (solution and linoleic acid model system) | DPPH, ORAC, linoleic acid oxidation (PV) | Fe | The Alcalase fraction, MW < 2 kDa demonstrated the highest DPPH. The linoleic acid oxidation was equally and significantly inhibited by Trypsin and Alcalase hydrolysates. Hydrolysates showed better chelating properties (Trypsin > Alcalase) than their fractions (MW < 2 kDa, and MW between 2 and 10 kDa). | Tsopmo et al. (2010) |
| In vitro (solution) | DPPH | Fe | AWFS showed the highest radical scavenging activity (71%) followed by peptide WAF, LPWRPATNVF, WAFS and YGIKVGYAIP with 55.7%, 50%, 47.3% and 44%, respectively. GGIF and GIFE showed the lowest DPPH activity. Chelation activity was LPWRPATNVF > AWFS > YGIKVGYAIP. | Zarei et al. (2014) |
| In vitro (solution) | TPC (FC), DPPH, ABTS, FRAP, PCL-ACW | NI | Strongest antioxidant capacity for the highest degree of hydrolysis (50%). DPPH value was 0.14 mg/mL (EC50), ABTS was 326 ± 5.77 μmol TEAC/g, TPC was 45.94–50.36 mg GAE/g, and the FRAP values were 10-fold lower than ascorbic acid. | Ng et al. (2013) |
| In vitro (solution) | DPPH | NI | Papain hydrolysate after 38 h hydrolysis exhibited both the highest degree of hydrolysis (91 ± 0.1%) and DPPH activity (73.5 ± 0.25%) compared to the other hydrolysates. Activity had reverse correlation with peptide size. | Zarei et al. (2012) |
| In vitro (solution and linoleic acid model system) | HRSA, DPPH, H2O2, SRSA, FRAP, linoleic acid oxidation (PV) | Fe | F4 and F5 showed the strongest scavenging and electron transfer capacities in comparison to F1, F2, F3. F5 possessed the strongest metal chelating activity. In comparison to GSH, fractions had less ability to scavenge free radicals but better capacity to chelate metals and inhibit linoleic acid oxidation. | Pownall et al. (2010) |
| In vitro (solution and linoleic acid and liposome model system) | FRAP, DPPH, linoleic acid oxidation (PV) and human LDL oxidation | Fe | The roasting enhanced the antioxidant activity and roasted products were much stronger when hydrolyzed by proteases. Hydrolysates showed reducing powers at a concentration of 1.0 mg/mL, almost equivalent to 0.02 mg BHA or α-tocopherol/ml. At a concentration of 1.0 mg/mL, hydrolysates showed chelating effect almost equal to 0.0075 mg/mL of EDTA. | Hwang et al. (2001) |
| In vitro (solution) | DPPH, HRSA, SRSA, Reducing power (Fe, Mo), anti-lipid peroxidation | Fe/Cu | Comparing the ultrasonic-assisted proteolysis with Alcalase hydrolysis, the former required less time and had higher antioxidant activities. | (Yu et al., 2012) |
| In vitro (solution, linoleic acid model system) | DPPH, FRAP, linoleic acid oxidation (PV) and human LDL oxidation | Fe | Proteolysis incubation time increase (up to 2 h), and then decrease antioxidative activity (up to 12 h). FII (3 kDa < MW < 5 kDa) had the highest antioxidant and chelation activities. Basic peptides from fraction FII exhibited higher antioxidative activity than the neutral or acidic peptides. | Hwang et al. (2010) |
| In vitro (solution and linoleic acid model system) and in cellulo | DPPH, FRAP, ORAC, linoleic acid oxidation (PV), CAA | Fe | The ORAC value of YGS was 3-fold higher than GSH, and it displayed a stronger protective effect on linoleic acid peroxidation. YGS showed negligible DPPH, FRAP, and no metal chelating ability. | (Zheng et al., 2012) |
| In vitro (solution) | ABTS, DPPH, HRSA, FRAP | Fe | Antioxidant activities of the peptide SDRDLLGPNNQYLPK was higher than hydrolysate, that was higher than the protein isolate. Except for chelation activity (51.20% vs 10.59%), the DPPH, ABTS, FRAP and HRSA activities of the peptide were lower than BHT or Trolox at the concentration of 1 mg/mL. | Agrawal et al. (2016) |
| In vitro (solution and linoleic acid model system), in cellulo and in vivo | DPPH, ABTS, HRSA, SRSA, ORAC, linoleic acid oxidation (PV), cytotoxicity, CAA | NI | FY efficiently quenched free radicals. YL and FY showed high ORAC (~3.5 μmol TE/mg). YL and FY had the ability to scavenge superoxide anion radicals, although weaker than GSH. YL and FY reduced lipid peroxidation (similar to GSH, much lower than BHA). | (Yang et al., 2018) |
| In vitro (solution and linoleic acid model system) | DPPH, HRSA, SRSA, ORAC, ABTS, FRAP, linoleic acid oxidation (PV) | NI | Strongest DPPH activity for the lowest MW with Pancreatin (MW < 1 kDa) whereas it was the reverse for other hydrolysates (MW > 10 kDa). Highest SRSA, HRSA, ABTS, ORAC activities for all hydrolysates at the lowest MW fractions, whereas the reduction capacity (FRAP) was better with high-MW fraction (>10 kDa). The low MW fractions (<5 kDa) were able to inhibit the initial lipid peroxidation. GSH was more effective than hydrolysates and fractions. | Olagunju et al. (2018) |
| In vitro (solution) and in cellulo | DPPH, ABTS, FRAP, CAA | NI | KWFCT had a higher FRAP and DPPH values than acetylated-QWFCT. Acetylated-QWFCT had a higher ABTS and cellular antioxidant activity. This indicated that Lys at N-terminal easily reacts with DPPH free radicals and Fe3+ (FRAP), and acetylated-Gln at N-terminal is sensitive to ABTS and ABAP free radicals. | (Yang, Li, et al., 2017) |
| In vitro (solution) and in cellulo | DPPH, ABTS, HRSA, cytotoxicity, CAA | NI | After pulsed electric field treatment, the DPPH and ABTS radical inhibition values of QDHCH were increased to 85.13 ± 0.17% and 95.45 ± 0.12%. The HRSA of QDHCH was increased by 10.53%. | Liang et al. (2017) |
| In vitro (solution and oil-in-water emulsion) | ABTS and lipid oxidation (TBARS) | NI | Low-polarity, or less hydrophilic peptides (rich in hydrophobic amino acids), were prevalent in strongly antiradical and antioxidative fractions. P50–F10, P50–F12, and P50–F13 exhibited the greatest ABTS activity (~350 μM TE at 200 μg/mL). | Cheng et al. (2010) |
| In vitro (solution and oil-in-water emulsion) | ABTS, emulsion physical stability | Fe/Cu | Pro and Leu, were contained in the peptides that exhibited high ABTS ability. Lys, Arg, Glu and Asp were able to chelate metal ions such as Fe2+ and Cu2+. Adsorbed peptides were mostly short oligopeptides composed of two to seven amino acids, of which SFDL(I)K matched the sequence of patatin. | Cheng et al. (2014) |
| In vitro (solution and linoleic acid model system) | DPPH, FRAP, linoleic acid oxidation (PV) | Fe | At 10 mg/mL, hydrolysates had increased DPPH activities from 21.89 to 85.27%, the reducing power increased from 0.21 to 0.48 (Abs700nm). Iron chelating ability was improved from 30.50 to 80.03% at 1 mg/mL. Hydrolysates showed better lipid peroxidation inhibition in the linoleic acid model system. Flavourzyme was the best to produce antioxidative peptides. | Venuste et al. (2013) |
| In vitro (solution and linoleic acid model system) | DPPH, FRAP, linoleic acid oxidation (PV) | Fe | The lowest MW peptides had stronger radical scavenging activity. DPPH value (IC50) of hydrolysate was 165 μg/mL (NB: phenolics still present), chelation capacity was of 7 mg/mL (IC50), the reducing power (1 nm at 0.1 mg/mL) was lower than BHA, ascorbic acid or tocopherol (1.2, 1.7, 0.6 nm respectively at 100 μg/mL). | He et al. (2012) |
| In vitro (solution) | DPPH | NI | The peptide PAGPF exhibited DPPH radical scavenging of 0.063 mg/mL (ED50). | (Zhang et al., 2009) |
| In vitro (solution) | ORAC | NI | Hydrolysates from Alcalase and Proteinase K, had high levels of free radical scavenging capacity. MW of peptide fractions were inversely related to the capacity. Peptides with sizes MW < 3 kDa had significantly reduced surface hydrophobicity, but showed much higher ORAC ability compared to the MW > 3 kDa peptides. | He et al. (2013) |
| In vitro (solution) | FRAP, DPPH, SRSA, HRSA | NI | The EC50 values of hydrolysate for DPPH, SRSA, and HRSA were 0.71, 1.05, and 4.92 mg/mL, respectively. The FRAP value was 0.51 (at 700 nm) at 2.00 mg/mL. | Pan et al. (2011) |
| In vitro (solution + liposome model system) | DPPH, HRSA, FRAP, inhibition of lipid peroxidation in a liposome model system (TBARS) | NI | The reducing power of RP55 and hydrolysate was higher than RP25. The ED50 of hydrolysate, RP25 and RP55 for DPPH were 72, 499 and 41 mg/mL, respectively. The ED50 for RP25 and RP55 for HRSA were 2.53 and 6.79 mg/mL, while the ED50 of RP55 and hydrolysate for inhibition of lipid peroxidation in liposomes system were 4.06 and 4.69 mg/mL. The inhibitory effect on lipid oxidation of RP55 was similar to that of ascorbic acid at a concentration of 5.0 mg/mL. | (Zhang et al., 2008) |
| In vitro (solution and linoleic acid model system) | ABTS, DPPH, SRSA, ORAC, linoleic acid oxidation (PV) | NI | Low MW peptides were the most effective. The DPPH and SRSA of the fraction (MW < 1 kDa) with Pepsin followed the same trend as GSH. | Alashi et al. (2014) |
| In vitro (solution) | ABTS | NI | The ABTS values (TE) of hydrolysate and each fraction (RSP-1, RSP-2, RSP-3, or RSP-4) were 0.168, 0.186, 0.140, 0.120 and 0.240 mg/mL, respectively. | (Yu et al., 2013) |
| In vitro (solution) | FRAP, SRSA, HRSA, lipid peroxidation (MDA) | NI | Hydrolysate had reducing activity (FRAP assay increases of ~1 Abs at 700 nm at 100 mg/mL), and scavenged > 9, 80 and 87% of hydroxyl radicals at 0.1, 100 and 250 mg/mL, respectively. The highest SRSA of hydrolysate and RSP1-3 were 80, 90, 35, and 80%, respectively, at concentrations of 0.5 (RSCH), 0.5 (RSP1), 0.05 (RSP2), and 2 mg/mL (RSP3). | Xue et al. (2009) |
| In vitro (solution) | FRAP, DPPH | NI | All three hydrolysates exhibited a concentration dependent DPPH activity with a maximum around 70% at 10 mg/mL. Reducing power were also concentration dependent with an absorbance increases <1 (700 nm) at 10 mg/.mL. | Cumby et al. (2008) |
| In vitro (solution) | ABTS, DPPH | NI | The scavenging activity of bromelain and protease against the DPPH radical (0.81 ± 0.002 and 0.60 ± 0.009 mM TE, respectively) was lower than the ABTS radical (2.89 ± 0.03 and 2.02 ± 0.06 mM TE, respectively). The enhanced antioxidant activity is likely the consequence of some low MW peptides or free amino acids with bromelain. | Selamassakul et al. (2016) |
| In vitro (solution) | DPPH, ABTS, FRAP | Fe | Digestion increased activities. Pepsin hydrolysate had DPPH = 80.18 ± 6.18 μmoL TE/g sample. F1 (MW < 3 kDa) showed the highest DPPH (66.25 ± 2.60 μmoL TE/g sample), FRAP (96.43 ± 3.88 μmoL FeSO4 equivalent/g sample) and ABTS (425.81 ± 2.59 TE/g sample). Yet, smallest fraction (F1) had the lowest chelating activity (22.23 ± 0.93 μmoL EDTA equivalent/g sample). | Phongthai et al. (2018) |
| In vitro (solution) | ABTS | Cu | Glutelin hydrolysates exhibited the highest ABTS (0.69 ± 0.04 μM trolox) and copper chelating (4.12 ± 0.01 mg EDTA) activities. The F4 fraction showed the highest ABTS (1.08 ± 0.03 mM trolox) and copper chelating (5.00 ± 0.02 mg EDTA) activities. The peptides with MW < 1500 Da and hydrophobic or aromatic N-terminal residues (e.g. SPFWNINAHS, MPVDVIANAYR, VVYFDQTQAQA, VEVGGGARAP) possibly contributed to the highest antioxidant activity. | Selamassakul et al. (2018) |
| In vitro (solution) | DPPH, ABTS, FRAP | NI | F4 of RRPB3 exhibited the highest antioxidant activity, with DPPH (IC50 = 0.144 mg/mL), ABTS (IC50 = 0.107 mg/mL) and FRAP (0.165 ± 0.011 mg/mL). The antioxidant activities of peptides within MW 500–1500 Da are higher than that of peptides above 1500 Da and peptides below 500 Da. RPNYTDA and TRTGDPFF showed a synergistic effect. | Yan et al. (2015) |
| In vitro (solution) | ORAC | NI | The antioxidant activities of denatured hydrolysates are significantly higher compared to native hydrolysates. The trypsin hydrolysate possessed the highest antioxidant activity (4.067 μmol of TE/mg protein). Highest antioxidant activity for peptides in F14/F15/F16, with an ORAC value of 22.9–24.9 nmol of TE. | Wattanasiritham et al. (2016) |
| In vitro (linoleic acid model system) | Linoleic acid oxidation (PV) | NI | Higher antioxidative activity of crude protein was due to the presence of phytic acid. The antioxidative activity did not increase with increasing DH, and hydrolysates with DH below 10% had higher antioxidative activity than those above 20%. | Adebiyi et al. (2008) |
| In vitro (solution) | ABTS | NI | DH inversely correlates with antioxidant capacity. Albumin hydrolysates had higher antioxidative activity than other protein fractions. YLAGMN had the highest antioxidative activity. | Adebiyi et al. (2009) |
| In vitro (solution) | DPPH, FRAP | NI | The best DPPH (IC50 = 0.98 mg/mL) and FRAP (IC50 = 0.159 mg/mL at 0.05 mg/mL) values were obtained with the lowest MW (<4 kDa). YSK exhibited strong scavenging activity on DPPH (IC50 = 0.15 mg/mL) and FRAP (0.125 at 0.05 mg/mL). | (Wang et al., 2017) |
| In vitro (solution) | FRAP, DPPH, HRSA | NI | The lowest MW (<5 kDa) fraction of the Protamex-Alcalase hydrolysate had the highest activity. PYK exhibited a DPPH value of IC50 = 0.12 mg/mL, a HRSA value of IC50 = 0.75 mg/mL, and a FRAP of ~1 abs (700 nm) at 0.5 mg/mL. Results were similar to GSH. | Hu et al. (2019) |
| In vitro (solution) | DPPH, HRSA, ABTS, FRAP | NI | Hydrolysate had certain HRSA activity (IC50 = 3.0 mg/mL), strong ABTS activity (IC50 = 35 μg/mL), scavenging DPPH ability (IC50 = 420 μg/mL), and FRAP absorption value reached 0.5 (700 nm) at 3.20 mg/mL. | (Yang et al., 2019) |
| In vitro (solution and linoleic acid model system) and in vivo | DPPH, ABTS, FRAP and linoleic acid oxidation (PV) | NI | SPH-I (MW < 3 kDa) exhibited the highest DPPH and ABTS radicals scavenging activities (IC50 of 350 μg/mL and 17.5 μg/mL, respectively), reducing power and the lipid peroxidation inhibition potential. | Cai et al. (2017) |
| In vitro (solution) | NI | Zn/Fe | The hydrolysates treated by trypsin had the highest metal chelating ability. The NCS peptide showed the highest zinc and iron chelating ability, which was higher than GSH. | (Wang et al., 2012) |
| In vitro (solution) | DPPH, ABTS | NI | The lowest MW (<3 kDa) fraction DSPH-V showed the highest efficiency. P4 had the best DPPH (IC50 = 2.793 ± 0.104 mg/mL) and ABTS (IC50 = 2.949 ± 0.069 mg/mL). SYPTECRMR, fragment of sesame 2 S albumins, showed the strongest DPPH (0.105 ± 0.018 mg/mL) and ABTS (0.004 mg/mL) radical scavenging activities. | (Lu et al., 2019) |
| In vitro (solution and linoleic acid model system) | DPPH, linoleic acid oxidation (TBARS) | NI | The lowest MW (<1 kDa) fraction showed the highest inhibition of lipid peroxidation (~60%) and the best DPPH radical scavenging activity (IC50 = 0.038 ± 0.002 mg/mL). In comparison, tocopherol and TBHQ were 0.018 ± 0.002 mg/mL and 0.016 ± 0.001 mg/mL, with inhibition of lipid peroxidation between 75 and 85%. | Das et al. (2012) |
| Ground meat model and in vitro (solution and oil-in-water emulsion) | DPPH, ORAC, FRAP, TPC (FC), lipid oxidation (PV, TBARS) | Fe | Hydrolysates displayed promising antioxidant capacity. Medium MW (3–10 kDa) hydrolysates exhibited the highest TPC, the best antioxidant activities, and effectively retarded lipid autoxidation in model emulsion and ground meat systems. | Xu et al. (2019) |
| In vitro (solution) | DPPH, ABTS, FRAP | Fe | Low MW fraction UF3 (<3 kDa) exhibited the strongest DPPH, ABTS, FRAP and Fe2+ chelating ability. Peptides VAITLTMK and VSKSVLVK exhibited the dominating radical scavenging capacity. | Agrawal et al. (2017) |
| In vitro (solution, β-carotene model system) | HRSA, ABTS, SRSA, FRAP, β-carotene bleaching | NI | Low MW fractions were the most active in β-carotene model system and as radical scavengers. | Moure et al. (2006) |
| In vitro (solution) and fat-rich food model (cooked ground beef) | ORAC, DPPH, lipid oxidation (TBARS) | Fe | NP-F1 (MW > 10 kDa) from neutral protease and AP-F3 (MW > 1 kDa) from alkaline protease exhibited good results with respect to meat peroxidation. Fractions MW > 10 kDa from Validase and neutral protease exhibited a good chelating activity. | (Zhang et al., 2010) |
| In vitro (oil-in-water emulsion) | TBARS | NI | Oxidized soybean protein hydrolysate and oxidized soybean protein were still able to retard TBARS formation in emulsions by as much as 52%. Oxidation of peptides and proteins did not significantly affect the emulsion physical stability, their distribution and the peptide adsorption at water-oil interface. | (Zhao and Xiong, 2015) |
| In vitro (solution) and In cellulo | DPPH, ABTS, ORAC, FRAP. Cell studies | NI | The peptides displayed DPPH (from 16.5 ± 0.5 to 20.3 ± 1.0 μM TE/μM), ABTS (from 3.42 ± 0.2 to 4.24 ± 0.4 mM TE/μM), ORAC (from 143 ± 2.1 to 171 ± 4.8 μM TE/μM), and FRAP (from 54.7 ± 1.2 to 79.0 ± 0.6 mM Fe2+/μM) activities. They showed inhibitory effects against intracellular reactive oxygen species generation in Caco-2 cells. | (Zhang et al., 2019) |
| In vitro (solution) and In cellulo | DPPH, ABTS, ORAC, FRAP, cytotoxicity, CAA. | Fe | Hydrolysate displayed DPPH (IC50 = 4.22 mg/mL), ABTS (IC50 = 2.93 mg/mL), reducing power, metal ion-chelating activities (IC50 = 0.67 mg/mL) and significantly inhibited the generation of intracellular reactive oxygen species in Caco-2 cells. After simulated gastrointestinal digestion, the activities were enhanced, except for the ABTS capacity. | (Zhang et al., 2018) |
| In vitro (liposomal system) | Liposome oxidation (TBARS) | NI | Nonhydrolyzed soy protein isolate possessed antioxidant activity. Preheated and hydrolyzed samples of Chymotrypsin and Flavourzyme (0.5 h) had the greatest inhibitory effect on lipid oxidation. | Penta-Ramos & Xiong (2002) |
| In vitro (linoleic acid model system) | Linoleic acid oxidation (PV) | NI | Strong antioxidant activity of histidine-containing peptides. LLPHH was the most active. | (Chen et al., 1995) |
| In vitro (solution) and in cellulo | ABTS, ORAC, CAA. | NI | Antioxidant activities has been demonstrated for fragments released from N-terminal and central regions of lunasin. | Indiano-Romacho et al. (2019) |
| In vitro (linoleic acid model system) | Linoleic acid oxidation (PV and TBARS) | NI | Antioxidant activities increased with decreasing MW of hydrolysate (highest with MW < 3 kDa). The strongest antioxidant peptide showed activity of 108.13%/mg for TBARS, and contained hydrophobic amino acids, such as Phe, Ala, and Pro. | (Park et al., 2010) |
| In vitro (linoleic acid model system) | Linoleic acid oxidation (PV + HPLC = linoleic acid, linoleic acid hydroperoxides, secondary oxidation products | NI | His and Pro play important roles in the antioxidant activity of synthetic peptides. Tocopherol, BHA, and BHT, potentiated the antioxidative activities of the peptides. | (Chen et al., 1996) |
| In vitro (solution) and in cellulo | DPPH, ABTS, ORAC, CAA | NI | SHECN had significantly higher antioxidant activity than LPFAM. The CAA value of SHECN was 776.22 μmol QE/100 g. SHECN also showed significant DPPH inhibition (70.18 ± 4.06%), ABTS inhibition (88.16 ± 0.76%), ORAC value of 0.090 ± 0.002 μmol TE/mg. | (Yang, Wang, et al., 2017) |
| In vitro (solution) | ABTS | NI | Highest MW fractions did not show significant activity. F7 (enriched in Tyr) was the highest with 78% scavenging property (~113 mg TEAC/g). TTYY showed 13.6% up to 59.6% radical scavenging property within a range of 0.18 mM–18 mM. | Beermann et al. (2009) |
| In vitro (solution) | β-carotene bleaching | Cu | Peptides with higher chelating activity contained His and Arg. More hydrophilic fractions were the most antioxidative. | Megías et al. (2008) |
| In vitro (solution) | HRSA, DNA damage assay | Fe | Low-MW fraction F-IV (<3 kDa) exhibited the strongest HRSA and Fe2+ chelating ability. Synthesized peptide YYIVS showed the highest HRSA. | (Zhang et al., 2014) |
| In vitro (solution) | HRSA, ORAC | Fe | Hydrolysate at 300 MPa for 60 min showed the strongest antioxidant activity. Low MW peptide fractions (<3 kDa) were mainly the contributors to antioxidant activity. ORAC values were HDSASGQY (123.06 μg TE/mL) ≥ YYMVSA (117.30 μg TE/mL) ≥ HDSESGQY ~ YYIVS ~ RYYDPL (113.97, 111.90 and 109.24 μg TE/mL, respectively). | (Zhang and Mu, 2017) |
| In vitro (solution) and in cellulo | ABTS, ORAC, CAA | NI | Highest activity for the lowest MW fractions (<3 kDa). ORAC values were in the order of TY > SGGY > SSE > VRN > NPAN > AHSVGP. TY and SGGY exhibited excellent ABTS (~6300 μmol TE/g) and ORAC (~800 μmol TE/g) values, equivalent to GSH. SGGY was effective to protect SH-SY5Y cells against oxidative damage induced by H2O2. | Feng et al. (2019) |
| In vitro (solution) | NI | Fe | LAGNPDDEFRPQ and VEDELVAVV showed strong chelation capacity. | Lv et al. (2017) |
| In vitro (solution and linoleic acid model system) | DPPH, HRSA, FRAP, linoleic acid oxidation (PV) | Fe | Pepsin hydrolysate (3 h) exhibited the highest antioxidant activities (IC50 of HRSA = 5.04 ± 0.19 mg/mL). Its metal chelating activity was higher than GSH, but lower (~20-fold) than EDTA. Highest antioxidant activity with the lowest MW fraction (<3 kDa), and the DPPH activity of ADAF (IC50 = 0.31 ± 0.03 mg/mL) was 6.65-fold higher than hydrolysate. | (Chen et al., 2012) |
| In vitro (solution) and in cellulo | ABTS, DPPH, ORAC | Fe | Higher ORAC values (mmoL TE/mg) with fraction D2 (4248 ± 62) compared to hydrolysate (1389.26 ± 57.13). Hydrolysate chelation of Fe2+ ions was 74 ± 2.03% at 2.00 mg/mL, much higher than GSH. | Gu et al. (2015) |
| In vitro (solution) and in cellulo | DPPH | Fe | Fraction MW < 1 kDa (WSPHs-I) showed the highest antioxidant activities. Peptides showed good antioxidant activity stability against the heat, pH and simulated gastro-intestinal digestion treatment. | Wen et al. (2019) |
| In vitro (solution and linoleic acid model system) | DPPH and inhibition of linoleic acid oxidation (TBARS) | NI | The hydrolysate and its UF fractions showed strong antioxidative activities in both assays. UF fractions were superior to the hydrolysate. Fraction MW < 5 kDa showed the best activity (similar to α-tocopherol). | (Wang et al., 2007) |
| In vitro (solution and linoleic acid model system) | DPPH, SRSA, HRSA, FRAP, inhibition of linoleic acid oxidation (PV) | Fe | The hydrolysate showed a relatively higher free radical-scavenging activities, a notable reducing power, and an antioxidant activity close to that of α-tocopherol in the linoleic acid model system. The hydrolysate had a strong iron binding capacity. | (Zhu et al., 2006) |
| In vitro (solution, β-carotene-linoleic acid model system) and cooked meat patty | DPPH, HRSA, ORAC, inhibition of β-carotene-linoleic acid oxidation (UV), lipid oxidation (TBARS) | Fe | Hydrolysate can suppress lipid oxidation in cooked pork meat patties during room temperature and chilled storage, and did not adversely affect sensory properties. All autofocusing fractions (especially the acids) showed higher chelating ability than hydrolysate. Acidic and basic fractions showed higher antioxidant activity than the hydrolysate. | (Park et al., 2012) |
NI: Not investigated, ESR: electron spin resonance, DPPH: diphényl-picrylhydrazyle, ABTS: 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, FRAP: ferric reducing antioxidant power, HSRA: hydroxyl radical scavenging activity, CAA: cellular antioxidant assay, PCL-ACW: Photochemiluminescence-antiradical capacity of water soluble substances, PV: peroxides value, TBARS: thiobarbituric acid reactive substances, SRSA: superoxide radical scavenging activity, SOD: superoxide dismutase, TAC: total antioxidant capacity, CAT: catalase, Tpx: total peroxides, GSH: glutathione, ABAP: 2,2-azobis(2-amidinopropane) dihydrochloride, BHA: butylated hydroxyanisole, DH; degree of hydrolysis, BHT: butylated hydroxytoluene, EDTA: ethylenediaminetetraacetic acid, ED50: median effective dose, IC50: half maximal inhibitory concentration, EC50: half maximal effective concentration, TE: Trolox equivalent, TEAC: Trolox equivalent antioxidant capacity.