Abstract:

 This study aimed to examine the effects of tea polyphenols (TP) and whey protein isolate (WPI) on the
preservation of surimi quality during cold storage. In this experiment, grass carp surimi was stored at 4 ℃ and tested for
total sulfhydryl content, thiobarbituric acid-reactive substances (TBARS) value, peroxide value (POV), total volatile basic
nitrogen (TVB-N) value, water content, and gel strength at different storage times (0, 1, 3, 5, 7, and 9 d). The effects of tea
polyphenols and whey protein isolate on the oxidation and quality of surimi were investigated. Experiments were divided
into 4 groups. Group A was used as control, and groups B, C and D were added with 0.05% TP, 5% WPI, and 0.05%
TP + 5% WPI, respectively. The results showed that compared with the control group, the addition of tea polyphenols
could significantly (P < 0.05) inhibit protein and fat oxidation, and its antioxidant effect in three experimental groups was
in the order of D > B > C; the addition of whey protein isoalte could significantly (P < 0.05) reduce the loss of water and
gel degradation, this effect in three experimental groups was in the order of D > C > B. Compared with the beginning of
cold storage, there were significant changes (P < 0.05) in all measured parameters from 3 d onwards, and all the results
showed that the effect of the addition of tea polyphenols and whey protein isolate together was the most obvious, leading
to a decrease of 4.3 mg/100 g in TVB-N and an increase of 260.07 g·mm in gel strength after cold storage for 7 d, and the
preservative effect was significant (P < 0.05). Therefore, tea polyphenols and whey protein isolate could be used together in
the production of surimi products for improved preservative effect.

Key words: tea polyphenols, whey protein isolate, surimi, cold storage, preservative effect