Effect of Tea Polyphenols on Grass Carp Rheological Characteristics

Abstract:

Fresh grass carp meat was treated with different concentrations of tea polyphenols (TP) and stored at 4°C. Spectrophotometry, texture analysis, rheometry, and scanning electron microscopy (SEM) was used in order to investigate changes in quality parameters such as emulsification, gelation, rheology, and ultra-microstructure during storage. The results indicated that adding more than 0.03% TP delayed the deterioration of emulsification properties and improves emulsion stability of grass carp fish protein. Adding more than 0.05% TP increases the gel strength of minced fish, lowers the storage modulus and loss modulus of fish products, eliminates free radicals produced by lipid oxidation, and delays the degradation rate of fish proteins. Within the experimental range, higher concentrations of TP resulted in greater protection of the rheological properties of fish protein, but without a dose-effect relationship. There were no significant differences between 0.05% and 0.07% TP groups. Therefore, taking into account the production cost, addition of 0.05% TP is recommended during cold storage of grass carp to preserve the quality.