# Deodorization of Tuna Peptides by Hydrogen Peroxide Oxidation

## TL;DR

This study shows how hydrogen peroxide can remove the fishy smell from tuna peptides without harming their health benefits, making them suitable for use in cosmetics and food.

## Contribution

A mild and efficient hydrogen peroxide oxidation method is introduced to deodorize tuna peptides while preserving their antioxidant properties.

## Key findings

- Hydrogen peroxide treatment reduced the sensory odor score of tuna peptides from 5 to 2.48.
- Key odorants like octanal and heptanal were completely removed, with a 44.8–54.7% reduction in other volatile compounds.
- Deodorized peptides retained high antioxidant activity (91.5% ABTS and 78.3% DPPH scavenging rates).

## Abstract

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.