Dual Cryoprotection of Gelatin-Tea Polyphenol Microgels on Surimi by Targeting for Ice Inhibition and Component Stabilization

Abstract

In this study, the gelatine-polyphenol microgels with dual cryoprotections were constructed by regulating the ratio of gelatin to tea polyphenols (1:50~1:250). The physicochemical attributes, water diffusivity and ice recrystallization inhibition (IRI) ability of microgels were investigated. The cryoprotective roles of microgels with various additions (1%, 2.5% and 4%, w/w) on surimi were studied. The results suggested that increased gelatin reduced the size and enhanced viscosity. Except for high viscosity and DPPH activity, the GP-5 group also showed great IRI ability and reduced water diffusion. Furthermore, addition of 2.5% of GP-5 microgel (2.5 G group) had a comparable TVB-N, TBARS, sulfhydryl contents and Ca2+-ATP activity with group containing commercial antifreeze (S group). Compared to uneven free water distribution of control group, S and 2.5 G group show more even immobilized-water distribution. Thereafter, the dual cryoprotective roles of microgels for surimi provide some inspiring references for the development of the desired antifreeze.

Keywords: Gelatin-tea polyphenol microgels, Dual cryoprotection, Ice crystal inhibition, Component stabilization, Frozen surimi