Oyster Mushroom (Pleurotus ostreatus) Stipe Peptides as in-vitro Radical Scavenging, Ferrous Iron Chelating, & Ferric Reducing Antioxidant Compounds
Ferrous iron chelating, ABTS radical scavenging, and ferric reducing antioxidant activity of mushroom stipe peptides obtained using Protamex® and V8 protease has not been investigated. Additionally, the effects of peptides on protein carbonyl formation during myofibrillar oxidation is unknown. Oxidation of lysine, arginine, and proline in myofibrillar protein from red meat results in reduced meat quality owing to changes in water composition. Therefore, the objective of this study was to compare the antioxidant performance of <1 kDa and 1-3 kDa mushroom peptides obtained by Protamex®-V8 hydrolysis against mushroom hydrolysate, mushroom protein, and mushroom stipe for radical scavenging, ferrous chelating, and ferric reducing activity, as well as their effects on protein carbonyl formation within a protein oxidation system. <1 kDa peptides exhibited significantly higher (p < 0.05) in-vitro ferrous iron chelating activity and ABTS radical scavenging activity as compared to mushroom stipe and 1-3 kDa peptides. Whereas, 1-3 kDa peptides demonstrated significantly higher (p < 0.05) in-vitro ferric reducing power as compared to mushroom stipe and <1 kDa peptides. During myofibrillar oxidation, mushroom protein comprising radical promoting enzymes promoted oxidation on all days of analysis. Mushroom stipe and <1 kDa peptides significantly promoted (p < 0.05) oxidation on day 0 and day 3, respectively. In contrast, 1-3 kDa peptides exhibited the greatest reduction in protein carbonyl formation by 34.7% as compared to mushroom stipe, hydrolysate, and <1 kDa peptides on day 9. Overall, the study demonstrates that mushroom stipe peptides may have potential use in the food industry as a natural antioxidant compound.
antioxidants, mushroom stipe, myofibrillar protein, peptides, protein carbonyls, Food Biotechnology, Food Chemistry, Meat Science
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