Deodorization of Tuna Peptides by Hydrogen Peroxide Oxidation

Tuna peptides possess significant bioactivity but are limited by their persistent fishy odor. This study employed mild oxidation with medical-grade hydrogen peroxide (3% H₂O₂) to deodorize tuna peptides. The optimal parameters determined through single-factor and orthogonal experiments were 798 mmol/L H₂O₂, 35 °C, and 20 min. Under these conditions, the sensory score decreased markedly from 5 (very strong odor) to 2.48 (slight odor). Solid-phase microextraction and gas chromatography/mass spectrometry (SPME-GC/MS) analysis confirmed the complete removal of key odorants such as octanal and heptanal, along with a 44.8-54.7% reduction in other volatile compounds. Importantly, the treated peptides retained substantial antioxidant activity, with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging rates of 91.5% and 78.3%, respectively. Successful incorporation of the deodorized peptides into a moisturizer demonstrated effective and lasting odor reduction. The proposed method offers an efficient, mild, and industrially viable strategy to expand the application of tuna peptides in functional cosmetics and foods.