Quality characteristics of common carp (Cyprinus carpio) surimi and kamaboko and the role of sarcaoplasmic proteins

This study was carried out to determine the characteristics of common carp surimi. In Australia, common carp (Cyprinus carpio) is an environmental pest, strongly coloured (dark-muscle fish), large (2-3 kg), low cost (AUD 2.5/kg) and not highly valued as it is every where else. Surimi could add value to carp, but the colour would have to be modified as surimi manufacturers prefer white coloured flesh. So, firstly the efficiency of Hydrogen peroxide (H2O2; 1-3% v/v) solution at alkaline side of pH (7.0-11.5) on whitening of light fillets of common carp was examined. The whiteness (L*-3b*) of surimi produced from treated (3% H2O2, pH 8.2) common carp light fillets was significantly (p less than 0.05) greater than that of threadfin bream surimi and was not significantly different to that of Alaska pollock. Based on a temperature sweep test, a similar pattern in G of tested surimi wa s observed which started at ca. 47?C and was completed at ca. 73-74?C. However, threadfin bream kamaboko showed better texture profile characteristics (hardness and gel strength) than that of the other kamaboko tested. To improve the quality of common carp surimi and kamaboko, alternative methods were applied such as modified conventional method (MCM), alkaline-aided method (AAM) and pH modified method (PMM) and the resultant surimi and kamaboko were compared with those produced by the traditional method (TM). In MCM each washing cycle was followed by a centrifugation step for a more effective dewatering and removal of sarcoplasmic proteins (Sp-P). Kamaboko prepared from MCM was whiter and had significantly (p less than 0.05) improved textural characteristics (hardness and gel strength) than that from TM, AAM and PMM. Furthermore, SEM of surimi and kamaboko showed higher number of polygonal structure/mm2 in the gel matrix of MCM kamaboko, as a result of more cross-linking of the myofibrillar proteins, than that recorded for TM, AAM and PMM samples tested. Finally, this study examined the effect of adding common carp sarcoplasmic proteins (Sp-P) on the gel characteristics of threadfin bream surimi and kamaboko. Based on the temperature sweep test, the depths of the valley in the G thermograph of the gels decreased as the concentration of added Sp-P increased from 5% to 35%. Storage modulus (G) of the gels showed greater elasticity in the samples with added Sp-P compared with the control samples without added Sp-P. Furthermore, the breaking force and breaking distance and consequently gel strength of the resultant kamaboko were improved, significantly (p less than 0.05) with added Sp-P. Thus, added Sp-P did not interfere with the gelling of myofibrillar proteins during sol-gel transition phase and was associated with textural quality enhancement for the resultant kamaboko. However, the addition of freeze-dried Sp-P from the dark muscle of the carp decreased the whiteness of the resultant surimi. Furthermore, the gel strength could not be associated with either the number of polygonal structures/mm2 or the area of the polygonal structures

Alternative techniques for producing a quality surimi and kamaboko from common carp (cyprinus carpio)

The demand for surimi and kamaboko is increasing in the world at the same time as the supply of the fish traditionally used has declined. In an effort to increase the range and hence supply of fish used, factors increasing the quality of surimi and kamaboko from common carp were investigated. The best surimi and kamaboko characteristics were produced by a modified conventional method (MCM) rather than traditional method (TM), alkaline-aided method (AAM), and pH modified method (PMM). MCM processing used centrifugation instead of decanting and filtering to optimize dewatering and remove the sarcoplasmic proteins (Sp-P). The temperature sweep test, at the end of sol-gel transition stage (at 75 °C), showed significantly (P < 0.05) greater G' for the kamaboko from MCM than that from other methods tested. Furthermore, the greatest and the least gel strengths were obtained with MCM and TM kamaboko, respectively. The protein recovery was about 67%, 74%, 87%, and 92% for TM, AAM, MCM, and PMM, respectively. TM and MCM resulted in the removal of Sp-P as determined by SDS-PAGE. The superiority of MCM kamaboko gel characteristics was supported by scanning electron micrographs (SEM) of the gel, which showed a significantly (P < 0.05) greater number of polygonal structures than for the TM kamaboko, which had the fewest and largest polygonal structures. The pH-shifting methods improved the textural quality of the resultant kamaboko compared with TM. However, a simple modification (centrifugation compared with decanting) by MCM in the surimi process can further improve the quality of the surimi and kamaboko gels. Furthermore, because it removed Sp-P and still preserved gel strength, it suggests that Sp-P are not required for gel strength

Colour improvement of common carp (Cyprinus carpio) fillets by hydrogen peroxide for surimi production

The preferred colour for surimi is white, but surimi prepared from light fillets of common carp (Cyprinus carpio) is slightly pink. Hydrogen peroxide (H2O2; 1-3% v/v) with and without sodium tri-polyphosphate (STP; 1-2% w/v) was added to a sodium carbonate bath (pH 7.0-11.5) resulting in a final pH range of 4.4-10.1 which was injected into carp fillets. After soaking and tumbling for 30 min at 4-10 °C, the fillets were evaluated for colour and water holding capacity (WHC). Fillets tumbled with treatment solution with different pH levels (7.0-11.5), but with no H2O2 or STP added, had improved colour with significantly (P < 0.05) higher L* compared with untreated fillets as the control. However, the colour improvement [(L* and colour deviation (?E)] was not significantly different (P > 0.05) within the pH levels (7.0-11.5) trialled. With increasing H2O2 levels (1-3%), fillets became lighter and ?E increased significantly (P < 0.05), especially with a 3% H2O2 treatment at pH of 10.5 (adjusted pH before H2O2 addition, actual pH after H2O2 addition was 8.2). The whiteness (L*-3b*) of kamaboko produced from treated (3% H2O2, pH 10.5) common carp light fillets was not significantly different to that of kamaboko from Alaska pollock and threadfin bream. Treatments combining H2O2 (3%) with STP (1-2%) significantly reduced the L* value obtained in comparison with fillets treated with only H2O2 (3%). Similarly, fillets treated with STP (1%) alone, resulting in lower L* values, irrespective of treatment pH (7.0-11.5). WHC, an indicator of the quality of the fillet texture, increased from 816 g/kg at pH 7.0 without STP to 841 g/kg at pH 11.5 with 1% STP. Treatment with H2O2 (without STP) decreased the WHC of the fillets