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

Authors


*Fax: +61 3 9925 5241; e-mail: l.gorczyca@rmit.edu.au

Summary

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 (< 0.05) higher L* compared with untreated fillets as the control. However, the colour improvement [(L* and colour deviation (ΔE)] was not significantly different (> 0.05) within the pH levels (7.0–11.5) trialled. With increasing H2O2 levels (1–3%), fillets became lighter and ΔE increased significantly (< 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.

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