Antioxidant activity of cod (Gadus morhua) protein hydrolysates: Fractionation and characterisation of peptide fractions

Abstract

This study aimed to characterise peptide fractions (>5kDa, 3-5kDa and <3kDa) with antioxidative activity obtained from a cod protein hydrolysate. The free amino acids in all fractions were dominated by Ala, Gly, Glu and Ser. The total amino acid composition had high proportions of Lys, Ala and Glu. The 3-5kDa and <3kDa fractions were further fractionated by size exclusion chromatography. All sub-fractions showed high Fe(2+) chelating activity. The DPPH radical-scavenging activity of the 3-5kDa fraction was exerted mainly by one sub-fraction dominated by peptides with masses below 600Da. The DPPH radical-scavenging activity of the <3kDa fraction was exerted by sub-fractions with low molecular weight. The highest reducing power was found in a sub-fraction containing peptides rich in Arg, Tyr and Phe. Both free amino acids and low molecular weight peptides thus seemed to contribute to the antioxidative activity of the peptide fractions, and Tyr seemed to play a major role in the antioxidant activity.

Factors Affecting Antioxidant Activity of Amino Acids in Soybean Oil at Frying Temperatures

“…Iron(III) 2‐ethylhexanoate, iron(III) acetylacetonate, copper(II) 2‐ethylhexanoate, and copper(II) acetylacetonate were chosen as metal sources for their solubility in oil. Two amino acids, L‐tryptophan and L‐lysine, were used at 11 mM, of which the metal chelation activity has been well studied . Table shows oxidation of metal‐containing SBO and the effect by L‐tryptophan and L‐lysine in the presence of a metal.…”

Effects of washing and membrane removal pretreatments on the antioxidant properties of grass carp (Ctenopharyngodon idella) protein hydrolysates produced by in vitro digestion

“…GPH5 (<1 kDa) showed the highest antioxidant activities. Many studies have reported that low‐molecular‐weight peptides showed higher antioxidant activity (Shi et al ., ; Sabeena Farvin et al ., ). The trend of antioxidant activity was as follows: GPH5 (<1 kDa) > GPH4 (1–3 kDa) > GPH1 (>10 kDa) > GPH2 & GPH3 (3–10 kDa), which was connected to the amount of hydrophobic and aromatic amino acids.…”

“…Protein hydrolysates from various sources have been reported to possess antioxidant activities, such as mackerel (Wu et al ., ), hoki (Mendis et al ., ), salmon (Ahn et al ., ), tilapia (Kangsanant et al ., ), cod (Sabeena Farvin et al ., ) and grass carp (Cai et al ., ). Grass carp ( Ctenopharyngodon idella ) is one of the ‘four major cultured fish species’ in China, and it has an annual production that exceeded 5.6 × 10 6 t in 2015, but it has not been developed into a high‐value product.…”

Bioactivity of Cod and Chicken Protein Hydrolysates before and after in vitro Gastrointestinal Digestion

“…Many studies have demonstrated earlier that protein hydrolysates from fi sh proteins are known for their antioxidant activity (6,(13)(14)(15)(16)(17). There are fewer reports about antioxidant activity of chicken protein-derived peptides (18,19), and only one study has compared fi sh with avian muscle hydrolysates (20); however, this study is without an in vitro digestion step.…”