Impacts of agar gum and fucoidan on gel properties of surimi products without phosphate.

Phosphate is widely used in surimi products to improve the gel properties. However, excess addition of phosphate occurs, which can harm the consumer's health. This study aimed to evaluate the effects of agar gum and fucoidan on maintaining the gel properties of surimi products instead of phosphate. Interestingly, our results showed that 0.125% of agar gum and fucoidan to replace phosphate could enhance water-holding capacity and maintain gel strength and textual properties of surimi products well. Especially at frozen storage for 1 year, 0.125% of agar gum reduced the expressible moisture content of surimi products by around 10% ( p  < .05). Sensory evaluation showed that 0.125% of agar gum and fucoidan instead of phosphate can improve tissue and fondness of surimi products in refrigerated storage for 24 h but not in frozen storage for 1 year. The addition of agar gum and fucoidan at a high concentration >0.50% increased the WHC, but significantly decreased gel strength and springiness of surimi products ( p  < .05). Particularly, 1.00% of agar gum and fucoidan reduced gel strength by around 20% ( p  < .05). It might be due to the destruction of the gel network structure of surimi protein following the excess addition of these polysaccharides. It can be concluded that 0.125% of agar gum and fucoidan can replace phosphate to develop high-quality surimi products, and excessive addition of them have negative effects.