Antioxidant mechanism, antibacterial activity, and functional characterization of peptide fractions obtained from barred mackerel gelatin with a focus on application in carbonated beverages

The present study aimed to use fish by-products to generate gelatin peptides with potential applications in carbonated beverages. After ultrafiltration, the F < 3 kDa (fraction < 3 kDa) showed the highest peptide concentration (227.22 mg/g) as well as antibacterial (MIC of <= 0.5 mg/mL) and antioxidant activities, including hydroxyl and superoxide radical scavenging, ferrous chelation, and ferric reduction (with IC50 values of 0.88, 1.04, 0.50 mg/mL, and 0.58, respectively). 2,2-diphenyl-1-picrylhydrazyl scavenging was the highest in the 3 < F < 10 kDa (IC50 of 0.64 mg/mL). In vitro gastrointestinal digestion significantly decreased all biological activities. Solubility, water holding capacity, and emulsifying activity of the F < 3 kDa were the highest while foaming properties and overfoaming were reversibly related to the molecular weight. All abovementioned properties, in addition to in vitro cytotoxicity analysis in different cell lines and better flavor characteristics, indicated that the F < 3 kDa could be safely and properly used as an ingredient for the fortification of carbonated beverages.

Automated summary

The study aimed to produce gelatin peptides from fish by-products for potential application in carbonated beverages, showing high antioxidant and antibacterial activities. The fraction < 3 kDa exhibited the highest peptide concentration and activities, but these biological activities were significantly decreased after in vitro gastrointestinal digestion. The F < 3 kDa could be safely used for fortification of carbonated beverages due to its properties and cytotoxicity analysis.