# Influence of Red Seaweed Polysaccharides on Gel Properties and In Vitro Antioxidants of Surimi Product Fish Balls

## TL;DR

This study explores how red seaweed polysaccharides affect the texture and antioxidant properties of fish balls made from surimi.

## Contribution

The study identifies optimal concentrations of carrageenan and agar gum to enhance gel properties and antioxidant activity in surimi products.

## Key findings

- Adding 0.75% carrageenan and 0.50% agar gum maximized gel strength by 28.84% and 12.08%, respectively.
- Excess PHP and BFP reduced gel strength by inhibiting protein cross-linking.
- PHP and BFP at 0.50% and 1.00% improved free radical scavenging activity after digestion.

## Abstract

The effects of red seaweed polysaccharides, e.g., carrageenan, agar gum, Porphyra haitanensis polysaccharide (PHP), and Bangia fusco-purpurea polysaccharide (BFP), on the physicochemical properties and in vitro antioxidants of silver carp surimi gels were studied. Adding appropriate concentrations of carrageenan and agar gum increased hydrophobic interactions, resulting in a denser and more uniform gel network as observed by SEM, and shortened the relaxation time of the fish balls, thus improving the gel strength and hardness of the products. When adding 0.75% carrageenan and 0.50% agar gum, the gel strength of the fish balls reached its maximum value, increasing by approximately 28.84% and 12.08%, respectively, compared to the control group (p < 0.05). However, with the over-addition of PHP and BFP, the cross-linking of surimi proteins was inhibited, resulting in a decrease in gel strength and hardness. In addition, red seaweed polysaccharide improved the free radical scavenging activity of fish balls, especially fish balls with 0.50% and 1.00% PHP and BFP exhibited better free radical scavenging activity after digestion. These findings offer insights and actionable strategies for enhancing the gel properties and function of surimi products with seaweed polysaccharides.