Effect of gelling on the active carbonyl compounds in surimi

Three kinds of active carbonyl compounds ( RCCs) , malondialdehyde ( MDA) , 4-hydroxy-2-hexenal ( HHE) , and4-hydroxy-2-nonenal ( HNE) in silver carp surimi and gel were determined using situ derivatization-SPME-GC-MS and the pentafluorophenyl hydrazine was the derivative agent. Furthermore, by adding pentafluorophenyl hydrazine to block RCCs-protein reaction, the effect of RCCs on surimi gel was analyzed. The content of MDA ( 0.42 ± 0.02) mg/kg, HHE ( 0.21 ±0.03) mg/kg were higher than HNE ( 0.07 ± 0.00) mg/kg in fresh silver carp surimi.The content of MDA, HHE, HNE in frozen surimi were ( 1.14 ± 0.03) , ( 0.86 ± 0.03) , and ( 0.18 ± 0.02) mg/kg, respectively, which were higher than that in fresh surimi.For gel from fresh surimi, because of heating, RCC content significantly increased ( p < 0.05) , however, for gel from frozen surimi, RCC content significantly ( p < 0.05) decreased.RCCs had no effect on gel strength of fresh surimi, however, after adding RCCs blockers, gel strength of frozen surimi ( 40 ℃, 1 h-90 ℃, 30 min) decreased from ( 243.52 ± 25.04) g × cm to ( 190.53 ±20.33) g × cm ( p < 0.05) , so RCCs helped to enhance the gel strength of frozen surimi.RCCs had no significant effect on water holding capability of surimi gel.