Improved physicochemical properties and product characteristics of tilapia surimi by tea polyphenols during chilled storage

Abstract

The decline of physicochemical properties of surimi during storage limits its application for surimi product processing. In this study, the effect of tea polyphenols (TP) on the physicochemical properties and product characteristics of tilapia surimi during chilled storage was studied. With the increase of storage time, the total volatile basic nitrogen, malondialdehyde, and protein degradation index obviously increased, while the pH value, total sulfhydryl content, protein solubility, water-holding capacity (WHC), hardness, and whiteness obviously decreased. The addition of TP, especially at 300 mg/kg, significantly inhibited the lipid and protein oxidation and protein degradation in tilapia surimi, followed by the improved WHC and hardness of its product especially in late storage (5–7 d). Principal component analysis showed that 300 mg/kg TP-treated tilapia surimi after 7 d storage showed similar properties to TP-free tilapia surimi after 2 d storage, suggesting the good effect of TP on prolonging its storage life. The correlation network model based on the Pearson's correlation analysis revealed that the inhibition of protein oxidation, polymerization, and degradation in tilapia surimi by TP contributed most to the improvement of WHC and hardness in its product. TP can be developed as a potential protector for the tilapia surimi during chilled storage.