Salt is a necessary condition to produce a surimi product that is based on the gelation of salt-soluble myofibrillar proteins. Recently, there has been a growing concern among consumers to consume healthy foods due to the threat of several chronic diseases caused by an unhealthy diet. Methods of reducing salt content out of concern for health issues caused by excessive sodium intake may affect the gel properties of surimi, as can many health-oriented food additives. Several studies have investigated different strategies to improve the health characteristics of surimi products without decreasing gel properties. This review reports recent developments in this area and how the gel properties were successfully maintained under reduced-salt conditions and the use of additives. This review of recent studies presents a great deal of progress made in the health benefits of surimi and can be used as a reference for further development in the surimi product processing industry. Graphical Abstract

Sturgeon hydrolysates (SH) dramatically decreased inflammatory cytokines, preserved intestinal structure, and increased beneficial bacteria by inhibiting NF-κB and MAPK activation and reshaping the gut microbiota.

This work studied the effects of KGM with different degrees of deacetylation (DDs) on the physicochemical properties of silver carp (Hypophthalmichthys molitrix) surimi gels. Compared with KGM, deacetylated KGM (DKGM) weakened the water-holding capacity, but increased the gel strength of surimi gels. The storage modulus (G′) and loss modulus (G′′) of surimi showed an upward trend, and the aggregation rate of surimi with DKGM changed. The number of ionic bonds of mixed surimi gels increased on the whole, but those of hydrogen bonds declined; a hydrophobic interaction was the main driving force, and improved with the DDs of DKGM. FT-IR results indicated that the deacetylation of KGM had a slight influence on the secondary structure of the proteins. SDS-PAGE results showed that DKGM enhanced the intensity of the main heavy chains of myosin and actin. Examination of the network structure of the surimi gels revealed that DKGM might combine around the filaments of myofibrillar proteins like a rosary through hydrophobic interactions and hydrogen bonding. As a consequence, the myfibrillar protein aggregation was changed and the microstructures of the surimi became more compact and fibrous. The results indicated that the deacetylation of KGM led to an increase in hydrophobicity, which influenced the hydrophobic interaction of the myofibrillar proteins. As a result, the aggregation of the myofibrillar proteins was promoted and the physico-chemical properties of the surimi gel were improved.

The gonad of jellyfish (Rhopilema esculentum Kishinouye), containing high protein content with a rich amino acid composition, is suitable for the preparation of bioactive peptides. Jellyfish gonad was hydrolysed with neutral protease to obtain jellyfish gonad protein hydrolysate (JGPH), which was then purified sequentially by ultrafiltration, gel filtration chromatography, and RP-HPLC. The peptides were characterized with HPLC-MS/MS. One peptide with amino acid sequence Ser-Tyr (SY) was identified and synthesized, which showed good ACE inhibitory and antioxidant activity. The IC₅₀ of this peptide on DPPH, ·OH, super oxygen anion scavenging activities, and ACE inhibitory activity are 84.623 μM, 1177.632 μM, 456.663 μM, and 1164.179 μM, respectively. The anchor in the binding site of SY and ACE C-domain (ACE-C) was obtained by molecular simulations. The results showed that the dipeptide purified from jellyfish gonad protein hydrolysates can be used as functional food material and is helpful in the study of antioxidant and inhibition of ACE.